United States v. Skrmetti

605 U.S. 495

• Court: Supreme Court of the United States
• Decided: June 18, 2025
• Docket: 23-477
• Status: Published

Opinion

PRELIMINARY PRINT

Volume 605 U. S. Part 2 Pages 495–608

OFFICIAL REPORTS OF

THE SUPREME COURT June 18, 2025

REBECCA A. WOMELDORF reporter of decisions

NOTICE: This preliminary print is subject to formal revision before the bound volume is published. Users are requested to notify the Reporter of Decisions, Supreme Court of the United States, Washington, D. C. 20543, pio@supremecourt.gov, of any typographical or other formal errors. OCTOBER TERM, 2024 495

Syllabus

UNITED STATES v. SKRMETTI, ATTORNEY GENERAL AND REPORTER FOR TENNESSEE, et al. certiorari to the united states court of appeals for the sixth circuit No. 23–477. Argued December 4, 2024—Decided June 18, 2025 In 2023, Tennessee joined the growing number of States restricting sex transition treatments for minors by enacting the Prohibition on Medical Procedures Performed on Minors Related to Sexual Identity, Senate Bill 1 (SB1). SB1 prohibits healthcare providers from prescribing, adminis- tering, or dispensing puberty blockers or hormones to any minor for the purpose of (1) enabling the minor to identify with, or live as, a purported identity inconsistent with the minor's biological sex, or (2) treating pur- ported discomfort or distress from a discordance between the minor's biological sex and asserted identity. At the same time, SB1 permits a healthcare provider to administer puberty blockers or hormones to treat a minor's congenital defect, precocious puberty, disease, or physical injury. Three transgender minors, their parents, and a doctor challenged SB1 under the Equal Protection Clause of the Fourteenth Amendment. The District Court partially enjoined SB1, fnding that transgender individu- als constitute a quasi-suspect class, that SB1 discriminates on the basis of sex and transgender status, and that SB1 was unlikely to survive intermediate scrutiny. The Sixth Circuit reversed, holding that the law did not trigger heightened scrutiny and satisfed rational basis review. This Court granted certiorari to decide whether SB1 violates the Equal Protection Clause. Held: Tennessee's law prohibiting certain medical treatments for transgen- der minors is not subject to heightened scrutiny under the Equal Pro- tection Clause of the Fourteenth Amendment and satisfes rational basis review. Pp. 509–526. (a) SB1 is not subject to heightened scrutiny because it does not clas- sify on any bases that warrant heightened review. Pp. 510–522. (1) On its face, SB1 incorporates two classifcations: one based on age (allowing certain medical treatments for adults but not minors) and another based on medical use (permitting puberty blockers and hor- mones for minors to treat certain conditions but not to treat gender dysphoria, gender identity disorder, or gender incongruence). Classi- fcations based on age or medical use are subject to only rational basis 496 UNITED STATES v. SKRMETTI

review. See Massachusetts Bd. of Retirement v. Murgia, 427 U. S. 307 (per curiam); Vacco v. Quill, 521 U. S. 793. The plaintiffs argue that SB1 warrants heightened scrutiny because it relies on sex-based classifcations. But neither of the above classif- cations turns on sex. Rather, SB1 prohibits healthcare providers from administering puberty blockers or hormones to minors for certain medi- cal uses, regardless of a minor's sex. While SB1's prohibitions refer- ence sex, the Court has never suggested that mere reference to sex is suffcient to trigger heightened scrutiny. And such an approach would be especially inappropriate in the medical context, where some treat- ments and procedures are uniquely bound up in sex. The application of SB1, moreover, does not turn on sex. The law does not prohibit certain medical treatments for minors of one sex while allowing those same treatments for minors of the opposite sex. SB1 prohibits healthcare providers from administering puberty blockers or hormones to any minor to treat gender dysphoria, gender identity disor- der, or gender incongruence, regardless of the minor's sex; it permits providers to administer puberty blockers and hormones to minors of any sex for other purposes. And, while a State may not circumvent the Equal Protection Clause by writing in abstract terms, SB1 does not mask sex-based classifcations. Finally, the Court rejects the plaintiffs' argument that, by design, SB1 enforces a government preference that people conform to expecta- tions about their sex. To start, any allegations of sex stereotyping are misplaced. True, a law that classifes on the basis of sex may fail heightened scrutiny if the classifcations rest on impermissible stereo- types. But where a law's classifcations are neither covertly nor overtly based on sex, the law does not trigger heightened review unless it was motivated by an invidious discriminatory purpose. No such argument has been raised here. And regardless, the statutory fndings on which SB1 is premised do not themselves evince sex-based stereotyping. Pp. 511–517. (2) SB1 also does not classify on the basis of transgender status. The Court has explained that a State does not trigger heightened consti- tutional scrutiny by regulating a medical procedure that only one sex can undergo unless the regulation is a mere pretext for invidious sex discrimination. In Geduldig v. Aiello, 417 U. S. 484, the Court held that a California insurance program that excluded from coverage certain disabilities resulting from pregnancy did not discriminate on the basis of sex. See id., at 486, 492–497. In reaching that holding, the Court explained that the program did not exclude any individual from beneft eligibility because of the individual's sex but rather “remove[d] one physical condition—pregnancy—from the list of compensable disabili- Cite as: 605 U. S. 495 (2025) 497

ties.” Id., at 496, n. 20. The California insurance program, the Court explained, divided potential recipients into two groups: “pregnant women and nonpregnant persons.” Id., at 497, n. 20. Because women fell into both groups, the Court reasoned, the program did not discrimi- nate against women as a class. See id., at 496, and n. 20. The Court concluded that, even though only biological women can become preg- nant, not every legislative classifcation concerning pregnancy is a sex- based classifcation. Id., at 496, n. 20. As such, “[a]bsent a showing that distinctions involving pregnancy are mere pretexts designed to ef- fect an invidious discrimination against the members of one sex or the other, lawmakers are constitutionally free to include or exclude preg- nancy from the coverage of legislation . . . on any reasonable basis, just as with respect to any other physical condition.” Id., at 496–497, n. 20. By the same token, SB1 does not exclude any individual from medical treatments on the basis of transgender status. Rather, it removes one set of diagnoses—gender dysphoria, gender identity disorder, and gen- der incongruence—from the range of treatable conditions. SB1 divides minors into two groups: those seeking puberty blockers or hormones to treat the excluded diagnoses, and those seeking puberty blockers or hormones to treat other conditions. While the frst group includes only

transgender individuals, the second encompasses both transgender and nontransgender individuals. Thus, although only transgender individu- als seek treatment for gender dysphoria, gender identity disorder, and gender incongruence—just as only biological women can become preg- nant—there is a “lack of identity” between transgender status and the excluded diagnoses. Absent a showing that SB1's prohibitions are pre- texts designed to effect invidious discrimination against transgender in- dividuals, the law does not classify on the basis of transgender status. Pp. 517–519. (3) Finally, Bostock v. Clayton County, 590 U. S. 644, does not alter the Court's analysis. In Bostock, the Court held that an employer who fres an employee for being gay or transgender violates Title VII's pro- hibition on discharging an individual “because of ” their sex. See id., at 650–652, 654–659. The Court reasoned that Title VII's “because of ” test incorporates the traditional but-for causation standard, which di- rects courts “to change one thing at a time and see if the outcome changes.” Id., at 656. Applying that test, the Court held that, “[f]or an employer to discriminate against employees for being homosexual or transgender, the employer must intentionally discriminate against individual men and women in part because of sex.” Id., at 662. In such a case, the employer has penalized a member of one sex for a trait or action that it tolerates in members of the other. 498 UNITED STATES v. SKRMETTI

The Court declines to address whether Bostock's reasoning reaches beyond the Title VII context—unlike the employment discrimination at issue in Bostock, changing a minor's sex or transgender status does not alter the application of SB1. If a transgender boy seeks testosterone to treat gender dysphoria, SB1 prevents a healthcare provider from ad- ministering it to him. If his biological sex were changed from female to male, SB1 would still not permit him the hormones he seeks because he would lack a qualifying diagnosis. The transgender boy could re- ceive testosterone only if he had a permissible diagnosis (like a congeni- tal defect). And, if he had such a diagnosis, he could obtain the tes- tosterone regardless of his sex or transgender status. Under the reasoning of Bostock, neither his sex nor his transgender status is the but-for cause of his inability to obtain testosterone. Pp. 519–522. (b) SB1 satisfes rational basis review. Under that standard, the Court will uphold a statutory classifcation so long as there is “any rea- sonably conceivable state of facts that could provide a rational basis for the classifcation.” FCC v. Beach Communications, Inc., 508 U. S. 307, 313. SB1 clearly meets that standard of review. Tennessee deter- mined that administering puberty blockers or hormones to minors to treat gender dysphoria, gender identity disorder, or gender incongru- ence carries risks, including irreversible sterility, increased risk of dis- ease and illness, and adverse psychological consequences. The legisla- ture found that minors lack the maturity to fully understand these consequences, that many individuals have expressed regret for undergo- ing such treatments as minors, and that the full effects of such treat- ments may not yet be known. At the same time, the State noted evi- dence that discordance between sex and gender can be resolved through less invasive approaches. SB1's age- and diagnosis-based classifcations are rationally related to these fndings and the State's objective of pro- tecting minors' health and welfare. The Court also declines the plaintiffs' invitation to second-guess the lines that SB1 draws. States have “wide discretion to pass legislation in areas where there is medical and scientifc uncertainty.” Gonzales v. Carhart, 550 U. S. 124, 163. Recent developments demonstrate the open questions that exist regarding basic factual issues before medical authorities and regulatory bodies in this area, underscoring the need for legislative fexibility. Pp. 522–525. (c) This case carries with it the weight of ferce scientifc and policy debates about the safety, effcacy, and propriety of medical treatments in an evolving feld. The Equal Protection Clause does not resolve these disagreements. The Court's role is not “to judge the wisdom, fairness, or logic” of SB1, Beach Communications, 508 U. S., at 313, but only to ensure that the law does not violate equal protection guarantees. It Cite as: 605 U. S. 495 (2025) 499

does not. Questions regarding the law's policy are thus appropriately left to the people, their elected representatives, and the democratic process. P. 525. 83 F. 4th 460, affrmed.

Roberts, C. J., delivered the opinion of the Court, in which Thomas, Gorsuch, Kavanaugh, and Barrett, JJ., joined, and in which Alito, J., joined as to Parts I and II–B. Thomas, J., fled a concurring opinion, post, p. 526. Barrett, J., fled a concurring opinion, in which Thomas, J., joined, post, p. 547. Alito, J., fled an opinion concurring in part and concurring in the judgment, post, p. 557. Sotomayor, J., fled a dissenting opinion, in which Jackson, J., joined in full, and in which Kagan, J., joined as to Parts I–IV, post, p. 578. Kagan, J., fled a dissenting opinion, post, p. 607.

Solici tor General Prelogar argued the cause for the United States. With her on the briefs were Assistant At- torney General Clarke, Deputy Solicitor General Fletcher, Yaira Dubin, Bonnie I. Robin-Vergeer, and Barbara A. Schwabauer. Chase B. Strangio argued the cause for respondents L. W. et al. urging vacatur. With him on the briefs were Joshua A. Block, James D. Esseks, Sruti J. Swaminathan, Ria Ta- bacco Mar, Louise Melling, Pratik A. Shah, Martine E. Cic- coni, Kristen E. Loveland, Cecillia D. Wang, David D. Cole, Lucas Cameron-Vaughn, Stella Yarbrough, Sasha Buchert, Jennifer C. Pizer, Camilla B. Taylor, Karen L. Loewy, Tara L. Borelli, Zach ZhenHe Tan, and T. James Salwen. J. Matthew Rice, Solicitor General of Tennessee, argued the cause for respondents Jonathan Skrmetti et al. With him on the brief were Jonathan Skrmetti, Attorney General, pro se, Whitney D. Hermandorfer, Steven J. Griffn, Gabriel Krimm, Assistant Solicitor General, Adam K. Mortara, Jef- frey M. Harris, and Cameron T. Norris.*

*Briefs of amici curiae urging reversal were fled for the State of Cali- fornia et al. by Rob Bonta, Attorney General of California, Michael J. Mongan, Solicitor General, Julie Veroff and Samuel T. Harbourt, Deputy Solicitors General, Kathleen Boergers, Supervising Deputy Attorney Gen- eral, Nimrod Pitsker Elias, Sean McGuire, and Stephanie T. Yu, Deputy 500 UNITED STATES v. SKRMETTI

Opinion of the Court

Chief Justice Roberts delivered the opinion of the Court. In this case, we consider whether a Tennessee law banning certain medical care for transgender minors violates the Equal Protection Clause of the Fourteenth Amendment. Attorneys General, and Alice X. Wang, Associate Deputy Solicitor Gen- eral, and by the Attorneys General for their respective jurisdictions as follows: Philip J. Weiser of Colorado, William Tong of Connecticut, Kath- leen Jennings of Delaware, Brian L. Schwalb of the District of Columbia, Anne E. Lopez of Hawaii, Kwame Raoul of Illinois, Aaron M. Frey of Maine, Anthony G. Brown of Maryland, Andrea Joy Campbell of Massa- chusetts, Dana Nessel of Michigan, Keith Ellison of Minnesota, Aaron D. Ford of Nevada, Matthew J. Platkin of New Jersey, Letitia James of New York, Ellen F. Rosenblum of Oregon, Michelle A. Henry of Pennsylvania, Peter F. Neronha of Rhode Island, Charity R. Clark of Vermont, and Robert W. Ferguson of Washington; for the American Bar Association by John P. Elwood, Andrew T. Tutt, Daniel Yablon, and William R. Bay; for the American Historical Association et al. by Kara N. Ingelhart; for the American Psychological Association et al. by Jessica Ring Amunson, De- anne M. Ottaviano, and Howard S. Suskin; for Conservative Offcials et al. by Brian T. Burgess and Jesse Lempel; for the Constitutional Ac- countability Center by Elizabeth B. Wydra, Brianne J. Gorod, and David H. Gans; for the Disability Rights Education & Defense Fund et al. by Claudia Center; for Equality Florida et al. by Rachel G. Miller-Ziegler and J. Max Rosen; for Families with Transgender Children by Peter T. Barbur; for Foreign Non-Proft Organizations Advocating for the Rights of Transgender People by Andrew Rhys Davies, Charles C. Bridge, and Eric L. Hawkins; for the Genders & Sexualities Alliance Network et al. by Julia R. Lissner, Lynly S. Egyes, Shawn Thomas Meerkamper, Dale Melchert, Milo Inglehart, and Melissa L. Cizmorris; for the Giffords Law Center to Prevent Gun Violence et al. by Janice Mac Avoy, Esther Sanchez-Gomez, Leigh Rome, Douglas N. Letter, and Shira Lauren Feld- man; for GRACE et al. by Boris Bershteyn and Sean Madden; for inter- ACT: Advocates for Intersex Youth by Jonah M. Knobler and Alexander L. Chen; for Kentucky Plaintiffs et al. by Stephanie Schuster, Justin D. Weitz, Jordan D. Hershman, Shannon Minter, Christopher F. Stoll, Corey Shapiro, William E. Sharp, and Jennifer L. Levi; for Members of Congress by Conor Tucker; for Professors of Law et al. by Kathleen R. Hartnett; for TransParent et al. by Benjamin G. Bradshaw, Deanna M. Rice, Rachel Chung, T. Brandon Waddell, Sarah Brewerton-Palmer, Cyn- thia Cheng-Wun Weaver, and Peter E. Perkowski; for the Trevor Project Cite as: 605 U. S. 495 (2025) 501

I A An estimated 1.6 million Americans over the age of 13 identify as transgender, meaning that their gender identity

et al. by Justin R. Rassi; for Yale Philosophers by Jessica Weisel, Anna- Rose Mathieson, and Amanda Shanor; for Dr. Erica E. Anderson, PhD, et al. by Samantha L. Chaifetz and Marie Bussey-Garza; for William Esk- ridge, Jr., et al. by Leslie Greathouse; for Elliot Page et al. by Sydney Duncan, Gabriel Arkles, Carmine D. Boccuzzi, Jr., and Howard S. Zelbo; and for 17 Healthcare Providers by Amelia T. R. Starr, James H. R. Win- dels, and Deborah S. Mazer. Briefs of amici curiae urging vacatur were fled for the American Academy of Pediatrics et al. by D. Jean Veta and William R. Isasi; for Experts on Gender Affrming Care by Craig Kon- noth; for Expert Researchers et al. by Alexander Shalom and Natalie J. Kraner; and for Legal Scholars et al. by Catherine E. Stetson and Kenneth Y. Choe. Briefs of amici curiae urging affrmance were fled for the State of Alabama by Steve Marshall, Attorney General, Edmund G. LaCour, Jr., Solicitor General, and A. Barrett Bowdre, Principal Deputy Solicitor Gen- eral; for the State of Kentucky et al. by Russell Coleman, Attorney Gen- eral of Kentucky, Matthew F. Kuhn, Solicitor General, John H. Heyburn, Principal Deputy Solicitor General, and Daniel J. Grabowski, Assistant Solicitor General, by Tim Griffn, Attorney General of Arkansas, Nicholas J. Bronni, Solicitor General, and Dylan L. Jacobs, Deputy Solicitor Gen- eral, by Theodore E. Rokita, Attorney General of Indiana, James A. Barta, Solicitor General, and John M. Vastag, Deputy Attorney General, and by the Attorneys General for their respective States as follows: Treg Taylor of Alaska, Ashley Moody of Florida, Chris Carr of Georgia, Raúl Labra- dor of Idaho, Brenna Bird of Iowa, Kris Kobach of Kansas, Liz Murrill of Louisiana, Lynn Fitch of Mississippi, Austin Knudsen of Montana, Mi- chael T. Hilgers of Nebraska, Drew Wrigley of North Dakota, Dave Yost of Ohio, Gentner Drummond of Oklahoma, Alan Wilson of South Caro- lina, Marty Jackley of South Dakota, Sean Reyes of Utah, Jason Miyares of Virginia, Patrick Morrisey of West Virginia, and Bridget Hill of Wyo- ming; for the State of Missouri by Andrew Bailey, Attorney General, Joshua M. Divine, Solicitor General, Reed C. Dempsey, Deputy Solicitor General, and Peter F. Donohue, Assistant Attorney General; for the State of Texas by Ken Paxton, Attorney General, Charles K. Eldred, Brent Web- ster, First Assistant Attorney General, Ralph Molina, Deputy First As- sistant Attorney General, Austin Kinghorn, Deputy Attorney General, 502 UNITED STATES v. SKRMETTI

does not align with their biological sex. See 1 App. 257– 259; 2 id., at 827. Some transgender individuals suffer from gender dysphoria, a medical condition characterized by persistent, clinically signifcant distress resulting from an in-

and Johnathan Stone; for the Florida House of Representatives by David Axelman; for Gov. Greg Gianforte by Anita Y. Milanovich; for Gov. Henry Dargan McMaster et al. by Thomas A. Limehouse, Jr., Wm. Grayson Lambert, and Tyra S. McBride; for the Governor of Texas by Greg Ab- bott, pro se, James P. Sullivan, and Jason Bramow; for the Alliance De- fending Freedom by John J. Bursch, James A. Campbell, and Cody S. Barnett; for the America First Legal Foundation by Jonathan F. Mitchell and Gene P. Hamilton; for the American Civil Rights Project by Daniel I. Morenoff; for the American College of Pediatricians et al. by Gene C. Schaerr and Edward H. Trent; for the American Principles Project by Theodore M. Cooperstein and Craig L. Parshall; for America's Frontline Doctors et al. by David A. Dalia; for America's Future et al. by William J. Olson, Jeremiah L. Morgan, Joseph W. Miller, Kerry L. Morgan, J. Mark Brewer, and Patrick M. McSweeney; for Citizens for Self-Gover- nance by Rita M. Peters and Michael Farris; for Concerned Women for America et al. by Christopher E. Mills; for the Defense of Freedom Insti- tute for Policy Studies by Donald A. Daugherty, Jr.; for Do No Harm by David H. Thompson and Brian W. Barnes; for the Ethics and Public Pol- icy Center by Eric N. Kniffn; for the Ethics and Religious Liberty Com- mission et al. by Jeffrey A. Hall and Ilya Shapiro; for the Family Action Council of Tennessee et al. by J. Thomas Smith; for the Family Research Council by Christopher E. Mills; for Fifty-six Physicians by Andrew D. Watkins and Edward M. Wenger; for the Frontline Policy Council et al. by Kristine L. Brown; for the Independent Council on Women's Sports et al. by William Bock III; for the Independent Women's Law Center by James M. Burnham, Sylvia May Mailman, and Emmett E. Robinson; for International Non-Proft Organizations Advocating for Families Impacted by Gender Dysphoria by Randall L. Wenger; for Liberty Counsel by Ma- thew D. Staver, Anita L. Staver, and Horatio G. Mihet; for the Manhattan Institute et al. by Ilya Shapiro; for the North Carolina Values Institute by Deborah J. Dewart and Tami Fitzgerald; for Our Duty–USA by Nicholas P. Miller; for Partners for Ethical Care et al. by Mary E. McAlister and Vernadette R. Broyles; for the Society for Evidence-Based Gender Medi- cine (SEGM) by Daniel J. Cragg; for State Legislators et al. by Trey Del- linger; for the United States Conference of Catholic Bishops et al. by Megan M. Wold; for Wisconsin Family Action et al. by Frederick W. Clay- brook, Jr., Steven W. Fitschen, and James A. Davids; for the Women's Cite as: 605 U. S. 495 (2025) 503

congruence between gender identity and biological sex. Left untreated, gender dysphoria may result in severe physi- cal and psychological harms. In 1979, the World Professional Association for Transgen- der Health (WPATH) (then known as the Harry Benjamin International Gender Dysphoria Association) published one of the frst sets of clinical guidelines for treating gender dys- phoria with sex transition treatments. See P. Walker et al., Standards of Care: The Hormonal and Surgical Sex Reas- signment of Gender Dysphoric Persons (1979), reprinted in 14 Archives of Sexual Behavior 79 (1985). The standards addressed two treatments in particular: hormonal sex reas- signment (the use of hormones to induce the development of physical characteristics of the opposite sex) and surgical sex reassignment (surgery of the genitalia and/or chest to ap- proximate the physical appearance of the opposite sex). See id., at 81, §§ 3.2–3.3. They recognized the extensive and sometimes irreversible consequences of hormonal therapy and sex reassignment surgery and acknowledged that some

Liberation Front by Elspeth B. Cypher; for Isabelle Ayala et al. by Joshua K. Payne and Jordan Campbell; for Joseph Burgo, PhD, et al. by Mitra N. Forouhar; for Christopher R. Green, pro se; for Kurt T. Lash by R. Trent McCotter; for Abigail Martinez by Kelly J. Shackelford, Jeffrey C. Mateer, David J. Hacker, and Jeremiah G. Dys. Briefs of amici curiae were fled for Advancing American Freedom et al. by J. Marc Wheat; for Citizens Defending Freedom by Jason C. Greaves; for the Claremont Institute's Center for Constitutional Jurispru- dence by John C. Eastman and Anthony T. Caso; for Clinical Practice Guideline Experts by Eugene E. Stearns; for Family Law and Constitu- tional Law Scholars by Brian R. Matsui and Kevin Barry, pro se; for the Larger Detransitioners Community et al. by Terry Lee Fowler; for the NAACP Legal Defense & Educational Fund, Inc., by Janai S. Nelson, Samuel Spital, Alexsis Johnson, Avatara A. Smith-Carrington, Molly M. Cain, Kacey Mordecai, and Robert Niles-Weed; for Scholars of Philosophy et al. by Dean R. Broyles; for Williams Institute Scholars by David S. Flugman and Corey Stoughton; for Women's Declaration International USA by Kara Dansky; for James F. Blumstein, pro se; and for Max Laz- zara by Sean P. Gates. 504 UNITED STATES v. SKRMETTI

individuals who undergo reassignment procedures later re- gret their decision to do so. See id., at 83, 85–86, §§ 4.1.1– 4.1.3, 4.4.2–4.4.3, 4.5.1. Among other things, the standards of care provided that hormonal and surgical sex reassign- ment treatments should be administered only to adults. See id., at 89, § 4.14.4. In 1998, WPATH revised its standards of care to permit healthcare professionals to administer puberty blockers (de- signed to delay the development of physical sex characteris- tics) and hormones to minors in “rar[e]” circumstances. S. Levine et al., The Standards of Care for Gender Identity Disorders (5th ed. 1998), reprinted in 11 J. Psychology & Human Sexuality 1, 20 (1999). Today, the standards discuss a range of factors regarding the provision of such treatments to minors. E. Coleman et al., Standards of Care for the Health of Transgender and Gender Diverse People, Version 8, 23 Int'l J. Transgender Health S1, S65–S66 (2022). The current standards recognize known risks associated with the provision of sex transition treatments to adolescents, includ- ing potential adverse effects on fertility and the possibility that an adolescent will later wish to detransition. See id., at S47, S57, S61–S62. They further state that there is “lim- ited data on the optimal timing” of sex transition treatments or “the long-term physical, psychological, and neurodevelop- mental outcomes in youth,” id., at S65, and note that “[o]ur understanding of gender identity development in adolescence is continuing to evolve,” id., at S44. In recent years, the number of minors requesting sex tran- sition treatments has increased. See 2 App. 644, 827–828. This increase has corresponded with rising debates regard- ing the relative risks and benefts of such treatments. Com- pare, e. g., Brief for State of California et al. as Amici Curiae 1–13, with Brief for Alabama as Amicus Curiae 1–9. In the last three years, more than 20 States have enacted laws ban- ning the provision of sex transition treatments to minors, while two have enacted near total bans. Cite as: 605 U. S. 495 (2025) 505

Meanwhile, health authorities in a number of European countries have raised signifcant concerns regarding the po- tential harms associated with using puberty blockers and hormones to treat transgender minors. In 2020, Finland's Council for Choices in Health Care found that “gender reas- signment of minors is an experimental practice” and that “the reliability of the existing studies” is “highly uncertain.” 2 App. 583–584 (alterations omitted); see id., at 715–722, 727–729. That same year, England's National Institute for Health and Care Excellence published reports fnding that the evidence for using puberty blockers to treat transgender adolescents is of “very low certainty” and that the long-term risks associated with using hormones to treat adolescents with gender dysphoria are “largely unknown.” Id., at 588– 589. In 2022, Sweden's National Board of Health and Wel- fare found that “the evidence on treatment effcacy and safety is still insuffcient and inconclusive” and that the “risks” of puberty blockers and hormones “currently out- weigh the possible benefts.” 1 id., at 339–340; see 2 id., at 584–587. And in 2023, the Norwegian Healthcare Investiga- tion Board concluded that the “research-based knowledge” for hormonal sex transition treatments for minors is “insuf- fcient,” while the “long-term effects are little known.” 1 id., at 341–342. B In March 2023, Tennessee joined the growing number of States restricting sex transition treatments for minors by enacting the Prohibition on Medical Procedures Performed on Minors Related to Sexual Identity, S. B. 1, 113th Gen. Assem., 1st Extra. Sess.; Tenn. Code Ann. § 68–33–101 et seq. (SB1). While the State's legislature acknowledged that dis- cordance between a minor's gender identity and biological sex can cause “discomfort or distress,” § 68–33–101(c), it identifed concerns regarding the use of puberty blockers and hormones to treat gender dysphoria in minors. In particu- lar, the legislature found that such treatments “can lead to 506 UNITED STATES v. SKRMETTI

the minor becoming irreversibly sterile, having increased risk of disease and illness, or suffering from adverse and sometimes fatal psychological consequences,” § 68–33–101(b), and that minors “lack the maturity to fully understand and appreciate” these consequences and may later regret under- going the treatments, § 68–33–101(h). The legislature fur- ther found that sex transition treatments were “being per- formed on and administered to minors in th[e] state with rapidly increasing frequency,” § 68–33–101(g), notwithstand- ing the fact that the full range of harmful effects associated with the treatments were likely not yet known, see § 68–33– 101(b). The legislature also noted that guidelines regarding sex transition treatments for minors had “changed substan- tially in recent years,” § 68–33–101(g), and that health au- thorities in Sweden, Finland, and the United Kingdom had “placed severe restrictions” on such treatments after deter- mining that there was “no evidence” that their benefts out- weigh their risks, § 68–33–101(e); see supra, at 505. Finally, the legislature determined that there is evidence that gender dysphoria “can be resolved by less invasive approaches that are likely to result in better outcomes.” § 68–33–101(c). SB1 responds to these concerns by banning the use of cer- tain medical procedures for treating transgender minors. In particular, the law prohibits a healthcare provider from “[s]urgically removing, modifying, altering, or entering into tissues, cavities, or organs of a human being,” or “[p]rescrib- ing, administering, or dispensing any puberty blocker or hor- mone,” § 68–33–102(5), for the purpose of (1) “[e]nabling a minor to identify with, or live as, a purported identity incon- sistent with the minor's sex,” or (2) “[t]reating purported discomfort or distress from a discordance between the mi- nor's sex and asserted identity,” § 68–33–103(a)(1). Among other things, these prohibitions are intended to “protec[t] mi- nors from physical and emotional harm” by “encouraging mi- nors to appreciate,” rather than “become disdainful of,” their sex. § 68–33–101(m). Cite as: 605 U. S. 495 (2025) 507

SB1 is limited in two relevant ways. First, SB1 does not restrict the administration of puberty blockers or hormones to individuals 18 and over. § 68–33–102(6). Second, SB1 does not ban fully the administration of such drugs to minors. A healthcare provider may administer puberty blockers or hormones to treat a minor's congenital defect, precocious (or early) puberty, disease, or physical injury. § 68–33–103(b) (1)(A). The law defnes the term “[c]ongenital defect” to in- clude an “abnormality present in a minor that is inconsistent with the normal development of a human being of the minor's sex,” § 68–33–102(1), but excludes from the defnitions of “[c]ongenital defect” and “disease” “gender dysphoria, gen- der identity disorder, [and] gender incongruence,” §§ 68–33– 102(1), 68–33–103(b)(2). SB1 contains three primary enforcement mechanisms. The law authorizes Tennessee's attorney general to bring against any person who knowingly violates SB1 an action “to enjoin further violations, to disgorge any profts received due to the medical procedure, and to recover a civil penalty of [$25,000] per violation.” § 68–33–106(b). SB1 further per- mits the relevant state regulatory authorities to discipline healthcare providers who violate the law's prohibitions. § 68–33–107. Finally, SB1 creates a private right of action that enables an injured minor or nonconsenting parent of an injured minor to sue a healthcare provider for violating the law. § 68–33–105. C Three transgender minors, their parents, and a doctor (plaintiffs) brought a pre-enforcement challenge to SB1. Among other things, the plaintiffs asserted that SB1 violates the Equal Protection Clause of the Fourteenth Amendment. They moved for a preliminary injunction preventing the law's bans on sex transition treatments for minors from going into effect. The United States intervened under 42 U. S. C. § 2000h–2, which authorizes the Federal Government to intervene in a private equal protection suit “if the Attor- 508 UNITED STATES v. SKRMETTI

ney General certifes that the case is of general public impor- tance.” See Memorandum Opinion and Order in No. 23–cv– 00376 (MD Tenn., May 16, 2023), ECF Doc. 108. The District Court partially enjoined enforcement of SB1's prohibitions. See L. W. v. Skrmetti, 679 F. Supp. 3d 668, 677 (MD Tenn. 2023). The court concluded that the plaintiffs lacked standing to challenge the law's ban on sex transition surgery for minors. Id., at 681–682. But the court held, as relevant, that the United States and plaintiffs were likely to succeed on their equal protection challenge to the law's prohibitions on puberty blockers and hormones. Id., at 682– 712. The court found that transgender individuals consti- tute a quasi-suspect class, that SB1 discriminates on the basis of sex and transgender status, and that SB1 was un- likely to survive intermediate scrutiny. Id., at 686–687, 698, 712. Having concluded that SB1 was likely unconstitutional on its face, the District Court issued a statewide injunction enjoining enforcement of all provisions of SB1 except for the private right of action and the law's ban on sex transition surgery. See id., at 680– 681, 716–718. Tennessee ap- pealed, and the Sixth Circuit stayed the preliminary injunc- tion pending appeal. L. W. v. Skrmetti, 83 F. 4th 460, 469 (CA6 2023). The Sixth Circuit reversed. As relevant, the Sixth Cir- cuit held that the United States and plaintiffs were unlikely to succeed on the merits of their equal protection claim. See id., at 479–489. The court frst found that SB1 does not clas- sify on the basis of sex because the law “regulate[s] sex- transition treatments for all minors, regardless of sex,” by prohibiting all minors from “receiv[ing] puberty blockers or hormones or surgery in order to transition from one sex to another.” Id., at 480. The court next declined to recognize transgender individuals as a suspect class, fnding that trans- gender individuals are neither politically powerless nor a dis- crete group defned by obvious, immutable, or distinguish- ing characteristics. Id., at 486–487. Finally, the court Cite as: 605 U. S. 495 (2025) 509

concluded that the United States and plaintiffs had failed to establish that animus toward transgender individuals as a class was the operative force behind SB1. See id., at 487– 488. The Sixth Circuit held that SB1 was subject to and survived rational basis review, fnding that Tennessee had offered “considerable evidence” regarding the risks associ- ated with the banned medical treatments and the faws in existing research. Id., at 489. Judge White dissented. Judge White would have held that the United States and plaintiffs were likely to succeed on the merits of their equal protection claim. Id., at 498. In her view, SB1 triggered heightened scrutiny because it “facially discriminate[s] based on a minor's sex as assigned at birth and on a minor's failure to conform with societal expectations concerning that sex.” Ibid. Judge White would have held that Tennessee had failed to “show an ex- ceeding[ly] persuasive justifcation or close means-ends ft” for the law's sex-based classifcations. Ibid. We granted certiorari to decide whether SB1 violates the Equal Protection Clause of the Fourteenth Amendment.1 602 U. S. 1037 (2024). II The Fourteenth Amendment's command that no State shall “deny to any person within its jurisdiction the equal protection of the laws,” U. S. Const., Amdt. 14, § 1, “must coexist with the practical necessity that most legislation clas- sifes for one purpose or another, with resulting disadvan- tage to various groups or persons,” Romer v. Evans, 517 U. S. 620, 631 (1996). We have reconciled the principle of

1 Following oral argument, the United States submitted a letter to the Court representing that the United States “has now determined that SB1 does not deny equal protection on account of sex or any other characteris- tic” but “believes that the confuence of several factors counsels against seeking to dismiss its case in this Court.” Letter from C. Gannon, Deputy Solicitor General, to S. Harris, Clerk of Court (Feb. 7, 2025). The plain- tiffs remain adverse to the state respondents. 510 UNITED STATES v. SKRMETTI

equal protection with the reality of legislative classifcation by holding that, “if a law neither burdens a fundamental right nor targets a suspect class, we will uphold the legisla- tive classifcation so long as it bears a rational relation to some legitimate end.” Ibid. We generally afford such laws “wide latitude” under this rational basis review, acknowledg- ing that “the Constitution presumes that even improvident decisions will eventually be rectifed by the democratic proc- esses.” Cleburne v. Cleburne Living Center, Inc., 473 U. S. 432, 440 (1985). Certain legislative classifcations, however, prompt height- ened review. For example, laws that classify on the basis of race, alienage, or national origin trigger strict scrutiny and will pass constitutional muster “only if they are suitably tai- lored to serve a compelling state interest.” Ibid. We have similarly held that sex-based classifcations warrant height- ened scrutiny. See United States v. Virginia, 518 U. S. 515, 533 (1996). While our precedent does not make sex a “pro- scribed classifcation,” ibid., we have explained that sex “generally provides no sensible ground for differential treat- ment,” Cleburne, 473 U. S., at 440, and that sex-based lines too often refect stereotypes or overbroad generalizations about the differences between men and women, see Sessions v. Morales-Santana, 582 U. S. 47, 62 (2017). We accordingly subject laws containing sex-based classifcations to interme- diate scrutiny, under which the State must show that the “classifcation serves important governmental objectives and that the discriminatory means employed are substantially re- lated to the achievement of those objectives.” Virginia, 518 U. S., at 533 (internal quotation marks omitted).

A We are asked to decide whether SB1 is subject to height- ened scrutiny under the Equal Protection Clause. We hold it is not. SB1 does not classify on any bases that warrant heightened review. Cite as: 605 U. S. 495 (2025) 511

1 On its face, SB1 incorporates two classifcations. First, SB1 classifes on the basis of age. Healthcare providers may administer certain medical treatments to individuals ages 18 and older but not to minors. Second, SB1 classifes on the basis of medical use. Healthcare providers may administer puberty blockers or hormones to minors to treat certain con- ditions but not to treat gender dysphoria, gender identity disorder, or gender incongruence. Classifcations that turn on age or medical use are subject to only rational basis re- view. See Massachusetts Bd. of Retirement v. Murgia, 427 U. S. 307, 312–314 (1976) (per curiam) (rational basis review applies to age-based classifcation); Vacco v. Quill, 521 U. S. 793, 799–808 (1997) (state laws outlawing assisted suicide “neither infringe fundamental rights nor involve suspect classifcations”). The plaintiffs argue that SB1 warrants heightened scru- tiny because it relies on sex-based classifcations. See Brief for Respondents in Support of Petitioner 20– 37. We disagree. Neither of the above classifcations turns on sex. Rather, SB1 prohibits healthcare providers from administering pu- berty blockers and hormones to minors for certain medical uses, regardless of a minor's sex. Cf. Vacco, 521 U. S., at 800 (“On their faces, neither New York's ban on assisting suicide nor its statutes permitting patients to refuse medical treatment treat anyone differently from anyone else or draw any distinctions between persons. Everyone, regardless of physical condition, is entitled, if competent, to refuse un- wanted lifesaving medical treatment; no one is permitted to assist a suicide.”). The plaintiffs resist this conclusion, arguing that SB1 cre- ates facial sex-based classifcations by defning the prohibited medical care based on the patient's sex. See Brief for Re- spondents in Support of Petitioner 22. This argument takes two forms. At times, the plaintiffs suggest that SB1 classi- 512 UNITED STATES v. SKRMETTI

fes on the basis of sex because its prohibitions reference sex. Alternatively, the plaintiffs contend that SB1 works a sex- based classifcation because application of the law turns on sex. Neither argument is persuasive. This Court has never suggested that mere reference to sex is suffcient to trigger heightened scrutiny. See, e. g., Tuan Anh Nguyen v. INS, 533 U. S. 53, 64 (2001) (“The issue is not the use of gender specifc terms instead of neutral ones. Just as neutral terms can mask discrimination that is unlaw- ful, gender specifc terms can mark a permissible distinc- tion.”). Such an approach, moreover, would be especially inappropriate in the medical context. Some medical treat- ments and procedures are uniquely bound up in sex. The Food and Drug Administration itself recognizes that “[r]e- search has shown that biological differences between men and women (differences due to sex chromosome or sex hor- mones) may contribute to variations seen in the safety and effcacy of drugs, biologics, and medical devices.” FDA, Sex as a Biological Variable (Jan. 30, 2025) (online source ar- chived at https://www.supremecourt.gov). Indeed, the agency frequently approves drugs for use by only one sex. See, e. g., FDA, FDA in Brief: FDA Encourages Inclusion of Male Patients in Breast Cancer Clinical Trials (Aug. 26, 2019) (online source archived at https://www.supremecourt .gov) (“many” breast cancer treatments approved for women only); FDA, FDA Approves Second Drug To Prevent HIV Infection as Part of Ongoing Efforts To End the HIV Epi- demic (Oct. 3, 2019) (online source archived at https://www. supremecourt.gov) (drug to prevent HIV not approved for women). In the medical context, the mere use of sex-based language does not sweep a statute within the reach of heightened scrutiny. We also reject the argument that the application of SB1 turns on sex. The plaintiffs and the dissent contend that an adolescent whose biological sex is female cannot receive puberty blockers or testosterone to live and present as a Cite as: 605 U. S. 495 (2025) 513

male, but an adolescent whose biological sex is male can, while an adolescent whose biological sex is male cannot re- ceive puberty blockers or estrogen to live and present as a female, but an adolescent whose biological sex is female can. See Brief for Respondents in Support of Petitioner 22; post, at 587–591 (Sotomayor, J., dissenting). So conceived, they argue, SB1 prohibits certain treatments for minors of one sex while allowing those same treatments for minors of the opposite sex. The plaintiffs and the dissent, however, contort the mean- ing of the term “medical treatment.” Notably absent from their framing is a key aspect of any medical treatment: the underlying medical concern the treatment is intended to ad- dress. The Food and Drug Administration approves drugs and requires that they be labeled for particular indications— the diseases or conditions that they treat, prevent, mitigate, diagnose, or cure. See 21 CFR §§ 201.57(c)(2), 314.50(a)(1) (2024). Different drugs can be used to treat the same thing (would you like Advil or Tylenol for your headache?), and the same drug can treat different things (take DayQuil to ease your cough, fever, sore throat, and/or minor aches and pains). For the term “medical treatment” to make sense of these various combinations, it must necessarily encompass both a given drug and the specifc indication for which it is being administered. See Brief for Respondents in Support of Petitioner 5 (noting that “treatments” for adolescents with gender dysphoria include “puberty-delaying medication and hormone therapy” (emphasis added)). When properly understood from the perspective of the in- dications that puberty blockers and hormones treat, SB1 clearly does not classify on the basis of sex. Both puberty blockers and hormones can be used to treat certain overlap- ping indications (such as gender dysphoria), and each can be used to treat a range of other conditions. Id., at 6–7. These combinations of drugs and indications give rise to var- ious medical treatments. When, for example, a transgender 514 UNITED STATES v. SKRMETTI

boy (whose biological sex is female) takes puberty blockers to treat his gender incongruence, he receives a different medical treatment than a boy whose biological sex is male who takes puberty blockers to treat his precocious puberty.2 SB1, in turn, restricts which of these medical treatments are available to minors: Under SB1, a healthcare provider may administer puberty blockers or hormones to any minor to treat a congenital defect, precocious puberty, disease, or physical injury, Tenn. Code Ann. § 68–33–103(b)(1)(A); a healthcare provider may not administer puberty blockers or hormones to any minor to treat gender dysphoria, gender identity disorder, or gender incongruence, see §§ 68–33– 102(1), 68–33–103(a)(1), (b)(2). The application of that prohi- bition does not turn on sex. Of course, a State may not circumvent the Equal Protec- tion Clause by writing in abstract terms. See Personnel Administrator of Mass. v. Feeney, 442 U. S. 256, 274 (1979) (explaining that both overt and covert sex-based classifca- tions are subject to heightened review). The antimiscege- nation law that this Court struck down in Loving v. Vir- ginia, 388 U. S. 1 (1967), would not have shed its race-based classifcation had it, for example, prohibited “any person from marrying an individual of a different race.” Such a law would still have turned on a race-based classifcation: It would have prohibited Mildred Jeter (a black woman) from marrying Richard Loving (a white man), while permitting a white woman to do so. The law, in other words, would still “proscribe generally accepted conduct if engaged in by mem- bers of different races.” Id., at 11. Here, however, SB1 does not mask sex-based classifca- tions. For reasons we have explained, the law does not pro-

2 We use “transgender boy” to refer to an individual whose biological sex is female but who identifes as male, and “transgender girl” to refer to an individual whose biological sex is male but who identifes as female. Cite as: 605 U. S. 495 (2025) 515

hibit conduct for one sex that it permits for the other. Under SB1, no minor may be administered puberty blockers or hormones to treat gender dysphoria, gender identity dis- order, or gender incongruence; minors of any sex may be administered puberty blockers or hormones for other purposes. Nor are we persuaded that SB1's prohibition on the pre- scription of puberty blockers and hormones to “[e]nabl[e] a minor to identify with, or live as, a purported identity incon- sistent with the minor's sex” or to “[t]rea[t] purported dis- comfort or distress from a discordance between the minor's sex and asserted identity,” Tenn. Code Ann. § 68–33–103(a), refects a sex-based classifcation, contra, post, at 587–591 (opinion of Sotomayor, J.). In the dissent's view, this lan- guage “plainly classifes on the basis of sex” because it “turns on inconsistency with a protected characteristic.” Post, at 588. The dissent analogizes to a hypothetical law that “pro- hibit[s] minors from attending any services, rituals, or assem- blies if done for the purpose of allowing the minor to identify with a purported identity inconsistent with the minor's reli- gion.” Ibid. (internal quotation marks omitted; emphasis deleted). Such a law, the dissent argues, would plainly clas- sify on the basis of religion. “Whether the law prohibits a minor from attending any particular religious service turns on the minor's religion: A Jewish child can visit a synagogue but not a church, while a Christian child can attend church but not the synagogue.” Ibid. But a prohibition on the prescription of puberty blockers and hormones to “[e]nabl[e] a minor to identify with, or live as, a purported identity inconsistent with the minor's sex,” Tenn. Code Ann. § 68–33–103(a)(1), is simply a prohibition on the prescription of puberty blockers and hormones to treat gender dysphoria, gender identity disorder, or gender incon- gruence. A law prohibiting attendance at a religious serv- ice “inconsistent with” the attendee's religion may trigger 516 UNITED STATES v. SKRMETTI

heightened scrutiny. A law prohibiting the administration of specifc drugs for particular medical uses does not. See Vacco, 521 U. S., at 799–808. Finally, we reject the plaintiffs' argument that, “by design, SB1 enforces a government preference that people conform to expectations about their sex.” Brief for Respondents in Support of Petitioner 23. The plaintiffs note that SB1's statutory fndings state that Tennessee has a compelling in- terest in “encouraging minors to appreciate their sex” and in prohibiting medical care “that might encourage minors to become disdainful of their sex.” Ibid. (quoting Tenn. Code Ann. § 68–33–101(m)). They argue that these fndings re- veal that the law operates to force conformity with sex. See Brief for Respondents in Support of Petitioner 23; see also id., at 52 (“SB1's purpose is . . . to force . . . boys and girls to look and live like boys and girls.” (internal quotation marks omitted)). To start, the plaintiffs' allegations of sex stereotyping are misplaced. True, a law that classifes on the basis of sex may fail heightened scrutiny if the classifcations rest on im- permissible stereotypes. See J. E. B. v. Alabama ex rel. T. B., 511 U. S. 127, 139, n. 11 (1994). But where a law's classifcations are neither covertly nor overtly based on sex, contrast, e. g., post, at 589–590, n. 8 (opinion of Sotomayor, J.) (referencing a hypothetical requirement that all children wear “sex-consistent clothing”), we do not subject the law to heightened review unless it was motivated by an invidious discriminatory purpose, see Personnel Administrator of Mass., 442 U. S., at 271–274; Arlington Heights v. Metropoli- tan Housing Development Corp., 429 U. S. 252, 264–266 (1977). No such argument has been raised here. See Tr. of Oral Arg. 57–59. Regardless, the statutory fndings to which the plaintiffs point do not themselves evince sex-based stereotyping. The plaintiffs fail to note that Tennessee also proclaimed a “legit- imate, substantial, and compelling interest in protecting mi- Cite as: 605 U. S. 495 (2025) 517

nors from physical and emotional harm.” Tenn. Code Ann. § 68–33–101(m). And they similarly fail to acknowledge that Tennessee found that the prohibited medical treatments are experimental, can lead to later regret, and are associated with harmful—and sometimes irreversible—risks. §§ 68– 33–101(b)–(e), (h). Tennessee's stated interests in “encour- aging minors to appreciate their sex” and in prohibiting med- ical care “that might encourage minors to become disdainful of their sex,” § 68–33–101(m), simply refect the State's con- cerns regarding the use of puberty blockers and hormones to treat gender dysphoria, gender identity disorder, and gender incongruence, see Brief for Respondents 26–27 (“Given high desistance rates among youth and the tragic `regret' of de- transitioners, it was not improper to conclude that kids bene- ft from additional time to `appreciate their sex' before em- barking on body-altering paths. Nor is it improper for the State to protect minors from procedures that `encourage them to become disdainful of their sex'—and thus at risk for serious psychiatric conditions.” (citations and alterations omitted)); L. W., 83 F. 4th, at 485 (“A concern about poten- tially irreversible medical procedures for a child is not a form of stereotyping.”). 2 The plaintiffs separately argue that SB1 warrants height- ened scrutiny because it discriminates against transgender individuals, who the plaintiffs assert constitute a quasi- suspect class. See Brief for Respondents in Support of Peti- tioner 37–38. This Court has not previously held that trans- gender individuals are a suspect or quasi-suspect class. And this case, in any event, does not raise that question be- cause SB1 does not classify on the basis of transgender sta- tus. As we have explained, SB1 includes only two classif- cations: healthcare providers may not administer puberty blockers or hormones to minors (a classifcation based on age) to treat gender dysphoria, gender identity disorder, or gen- der incongruence (a classifcation based on medical use). 518 UNITED STATES v. SKRMETTI

The plaintiffs do not argue that the frst classifcation turns on transgender status, and our case law forecloses any such argument as to the second. We have explained that a State does not trigger height- ened constitutional scrutiny by regulating a medical proce- dure that only one sex can undergo unless the regulation is a mere pretext for invidious sex discrimination. In Gedul- dig v. Aiello, 417 U. S. 484 (1974), for example, we held that a California insurance program that excluded from coverage certain disabilities resulting from pregnancy did not discrim- inate on the basis of sex. See id., at 486, 492–497. In reaching that holding, we explained that the program did not exclude any individual from beneft eligibility because of the individual's sex but rather “remove[d] one physical condi- tion—pregnancy—from the list of compensable disabilities.” Id., at 496, n. 20. We observed that the “lack of identity” between sex and the excluded pregnancy-related disabilities became “clear upon the most cursory analysis.” Id., at 497, n. 20. The California insurance program, we explained, di- vided potential recipients into two groups: “pregnant women and nonpregnant persons.” Ibid. Because women fell into both groups, the program did not discriminate against women as a class. See id., at 496, and n. 20. We thus con- cluded that, even though only biological women can become pregnant, not every legislative classifcation concerning pregnancy is a sex-based classifcation. Id., at 496, n. 20. As such, “[a]bsent a showing that distinctions involving preg- nancy are mere pretexts designed to effect an invidious dis- crimination against the members of one sex or the other, lawmakers are constitutionally free to include or exclude pregnancy from the coverage of legislation . . . on any reason- able basis, just as with respect to any other physical condi- tion.” Id., at 496–497, n. 20. By the same token, SB1 does not exclude any individual from medical treatments on the basis of transgender status but rather removes one set of diagnoses—gender dysphoria, Cite as: 605 U. S. 495 (2025) 519

gender identity disorder, and gender incongruence—from the range of treatable conditions. SB1 divides minors into two groups: those who might seek puberty blockers or hor- mones to treat the excluded diagnoses, and those who might seek puberty blockers or hormones to treat other conditions. See Tenn. Code Ann. § 68–33–103. Because only transgen- der individuals seek puberty blockers and hormones for the excluded diagnoses, the frst group includes only transgender individuals; the second group, in contrast, encompasses both transgender and nontransgender individuals. Thus, al- though only transgender individuals seek treatment for gen- der dysphoria, gender identity disorder, and gender incon- gruence—just as only biological women can become pregnant—there is a “lack of identity” between transgender status and the excluded medical diagnoses. The plaintiffs, moreover, have not argued that SB1's prohibitions are mere pretexts designed to effect an invidious discrimination against transgender individuals. Under these circum- stances, we decline to fnd that SB1's prohibitions on the use of puberty blockers and hormones exclude any individuals on the basis of transgender status.3 3 Finally, Bostock v. Clayton County, 590 U. S. 644 (2020), does not alter our analysis. In Bostock, we held that an em- 3 The dissent argues that our analysis “may well suggest that a law depriving all individuals who `have ever, or may someday, menstruate' of access to health insurance would be sex neutral merely because not all women menstruate.” Post, at 600 (opinion of Sotomayor, J.). But such a law is different from both SB1 and the law at issue in Geduldig. As we have explained, SB1 regulates certain medical treatments, see Tenn. Code Ann. § 68–33–103(a)(1); Geduldig involved a state disability insurance sys- tem that excluded certain pregnancy-related disabilities from coverage, see 417 U. S., at 487–489. The dissent's hypothetical law, in contrast, does not regulate a class of treatments or conditions. Rather, it regulates a class of persons identifed on the basis of a specifed characteristic. Nei- ther our analysis nor Geduldig speaks to a law that classifes on such a basis. 520 UNITED STATES v. SKRMETTI

ployer who fres an employee for being gay or transgender violates Title VII's prohibition on discharging an individual “because of ” their sex. See id., at 650–652, 654–659. We reasoned that Title VII's “because of ” test incorporates the traditional but-for causation standard, which “directs us to change one thing at a time and see if the outcome changes. If it does, we have found a but-for cause.” Id., at 656. Applying that test, we held that, “[f]or an employer to dis- criminate against employees for being homosexual or trans- gender, the employer must intentionally discriminate against individual men and women in part because of sex.” Id., at 662. In such a case, the employer has penalized a member of one sex for a trait or action that it tolerates in members of the other. Ibid. The plaintiffs urge us to apply Bostock's reasoning to this case. In their view, SB1 violates the Equal Protection Clause because it prohibits a minor whose biological sex is female from receiving testosterone to live as a male but allows a minor whose biological sex is male to receive testos- terone for the same purposes (and vice versa). Applying Bostock's reasoning, they argue that SB1 discriminates on the basis of sex because it intentionally penalizes members of one sex for traits and actions that it tolerates in another. See Brief for Respondents in Support of Petitioner 24–25. We have not yet considered whether Bostock's reasoning reaches beyond the Title VII context, and we need not do so here. For reasons we have already explained, changing a minor's sex or transgender status does not alter the applica- tion of SB1. If a transgender boy seeks testosterone to treat his gender dysphoria, SB1 prevents a healthcare pro- vider from administering it to him. See Tenn. Code Ann. § 68–33–103(a). If you change his biological sex from female to male, SB1 would still not permit him the hormones he seeks because he would lack a qualifying diagnosis for the testosterone—such as a congenital defect, precocious puberty, disease, or physical injury. The transgender boy Cite as: 605 U. S. 495 (2025) 521

could receive testosterone only if he had one of those permis- sible diagnoses. And, if he had such a diagnosis, he could obtain the testosterone regardless of his sex or transgender status. Under the reasoning of Bostock, neither his sex nor his transgender status is the but-for cause of his inability to obtain testosterone. The dissent counters that, whatever causal factors are at play, sex is at least one but-for cause of SB1's operation. See post, at 595–597 (opinion of Sotomayor, J.). To illus- trate this argument, the dissent posits a minor girl with fa- cial hair inconsistent with her sex. Under SB1, the dissent notes, a healthcare provider can prescribe puberty blockers or hormones to the minor to suppress her hair growth. Post, at 596. Change the minor's sex to male, the dissent reasons, and SB1 prevents the minor from obtaining the same drugs for the same purpose. Ibid. Any correspond- ing change in diagnosis, the dissent concludes, simply reveals that both sex and diagnosis are causal factors at “ `play.' ” Post, at 597 (quoting Bostock, 590 U. S., at 661). The dissent's reasoning overlooks a key distinction be- tween the operation of SB1 and the logic of Bostock. Under Bostock's reasoning, an employer who fres a homosexual male employee for being attracted to men while retaining the employee's straight female colleague has discriminated on the basis of sex because it has penalized the male em- ployee for a trait (attraction to men) that it tolerates in the female employee. See id., at 660. Bostock held that, in such a circumstance, sex is the but-for cause of the employ- er's decision—change the homosexual male employee's sex and he becomes a straight female whose attraction to men the employer tolerates. Not so with SB1. Consider again the minor girl with un- wanted facial hair inconsistent with her sex. If she has a diagnosis of hirsutism (male-pattern hair growth), a health- care provider may, consistent with SB1, prescribe her puberty blockers or hormones. But changing the minor's sex to 522 UNITED STATES v. SKRMETTI

male does not automatically change the operation of SB1. If hirsutism is replaced with gender dysphoria, the now-male minor may not receive puberty blockers or hormones; but if hirsutism is replaced with precocious puberty, SB1 does not bar either treatment. Unlike the homosexual male em- ployee whose sexuality automatically switches to straight when his sex is changed from male to female, there is no reason why a female minor's diagnosis of hirsutism automati- cally changes to gender dysphoria when her sex is changed from female to male. Under the logic of Bostock, then, sex is simply not a but-for cause of SB1's operation.

B The rational basis inquiry “employs a relatively relaxed standard refecting the Court's awareness that the drawing of lines that create distinctions is peculiarly a legislative task and an unavoidable one.” Massachusetts Bd. of Retirement, 427 U. S., at 314. Under this standard, we will uphold a statutory classifcation so long as there is “any reasonably conceivable state of facts that could provide a rational basis for the classifcation.” FCC v. Beach Communications, Inc., 508 U. S. 307, 313 (1993). Where there exist “plausible reasons” for the relevant government action, “our inquiry is at an end.” Id., at 313–314 (internal quotation marks omitted). SB1 clearly meets this standard. Tennessee determined that administering puberty blockers or hormones to a minor to treat gender dysphoria, gender identity disorder, or gen- der incongruence “can lead to the minor becoming irrevers- ibly sterile, having increased risk of disease and illness, or suffering from adverse and sometimes fatal psychological consequences.” Tenn. Code Ann. § 68–33–101(b). It fur- ther found that it was “likely that not all harmful effects associated with these types of medical procedures when per- formed on a minor are yet fully known, as many of these procedures, when performed on a minor for such purposes, Cite as: 605 U. S. 495 (2025) 523

are experimental in nature and not supported by high-quality, long-term medical studies.” Ibid. Tennessee determined that “minors lack the maturity to fully understand and ap- preciate the life-altering consequences of such procedures and that many individuals have expressed regret for medical procedures that were performed on or administered to them for such purposes when they were minors.” § 68–33–101(h). At the same time, Tennessee noted evidence that discordance between sex and gender “can be resolved by less invasive approaches that are likely to result in better outcomes for the minor.” § 68–33–101(c). SB1's age- and diagnosis- based classifcations are plainly rationally related to these fndings and the State's objective of protecting minors' health and welfare. § 68–33–101(a). The plaintiffs argue that SB1 fails even rational basis re- view because the law's classifcations are “so far removed from [Tennessee's] asserted justifcations that it is impossible to credit those interests.” Brief for Respondents in Support of Petitioner 51 (internal quotation marks and alterations omitted). In their view, Tennessee has failed to explain why it has banned access to puberty blockers and hormones “only where they would allow a transgender minor to `identify' or `live' in a way `inconsistent' with their `sex.' ” Id., at 52. This argument fails. As we have explained, there is a ra- tional basis for SB1's classifcations. Tennessee concluded that there is an ongoing debate among medical experts re- garding the risks and benefts associated with administering puberty blockers and hormones to treat gender dysphoria, gender identity disorder, and gender incongruence. SB1's ban on such treatments responds directly to that uncertainty. Contrast Cleburne, 473 U. S., at 448 (record did not reveal “any rational basis” for city zoning ordinance); Romer, 517 U. S., at 632 (“sheer breadth” of law was “so discontinuous with the reasons offered for it that the [law] seem[ed] inex- plicable by anything but animus toward the class it affect[ed]”). 524 UNITED STATES v. SKRMETTI

We also decline the plaintiffs' invitation to second-guess the lines that SB1 draws. It may be true, as the plaintiffs contend, that puberty blockers and hormones carry compara- ble risks for minors no matter the purposes for which they are administered. But it may also be true, as Tennessee determined, that those drugs carry greater risks when ad- ministered to treat gender dysphoria, gender identity disor- der, and gender incongruence. We afford States “wide dis- cretion to pass legislation in areas where there is medical and scientifc uncertainty.” Gonzales v. Carhart, 550 U. S. 124, 163 (2007). “[T]he fact the line might have been drawn differently at some points is a matter for legislative, rather than judicial, consideration.” Railroad Retirement Bd. v. Fritz, 449 U. S. 166, 179 (1980); see Dandridge v. Williams, 397 U. S. 471, 485 (1970) (“In the area of economics and social welfare, a State does not violate the Equal Protection Clause merely because the classifcations made by its laws are im- perfect.”); Lindsley v. Natural Carbonic Gas Co., 220 U. S. 61, 78 (1911) (“A classifcation having some reasonable basis does not offend against [the Equal Protection Clause] merely because it is not made with mathematical nicety or because in practice it results in some inequality.”). Recent developments only underscore the need for legisla- tive fexibility in this area. After Tennessee enacted SB1, a report commissioned by England's National Health Service (NHS England) characterized the evidence concerning the use of puberty blockers and hormones to treat transgender minors as “remarkably weak,” concluding that there is “no good evidence on the long-term outcomes of interventions to manage gender-related distress.” H. Cass, Independent Review of Gender Identity Services for Children and Young People: Final Report 13 (Apr. 2024). The report cautioned that “results of studies are exaggerated or misrepresented by people on all sides of the debate to support their view- point,” ibid., and concluded that the “current understanding of the long-term health impacts of hormone interventions is Cite as: 605 U. S. 495 (2025) 525

limited and needs to be better understood,” id., at 22. In response to the report, NHS England enacted prohibitions on the administration of puberty blockers to new patients under the age of 18 outside of research settings and insti- tuted a process for reviewing referrals for hormones for ado- lescents under the age of 16. See NHS England, Children and Young People's Gender Services: Implementing the Cass Review Recommendations 6–7 (Aug. 2024); Tr. of Oral Arg. 14–18. We cite this report and NHS England's response not for guidance they might provide on the ultimate question of United States law, see Schriro v. Summerlin, 542 U. S. 348, 356 (2004) (contemporary foreign practice is “irrelevant” to constitutional interpretation), but to demonstrate the open questions regarding basic factual issues before medical au- thorities and other regulatory bodies. Such uncertainty “af- ford[s] little basis for judicial responses in absolute terms.” Marshall v. United States, 414 U. S. 417, 427 (1974). And “[t]he calculus of effects, the manner in which a particular law reverberates in a society, is a legislative and not a judi- cial responsibility.” Personnel Administrator of Mass., 442 U. S., at 272. * * * This case carries with it the weight of ferce scientifc and policy debates about the safety, effcacy, and propriety of medical treatments in an evolving feld. The voices in these debates raise sincere concerns; the implications for all are profound. The Equal Protection Clause does not resolve these disagreements. Nor does it afford us license to decide them as we see best. Our role is not “to judge the wisdom, fairness, or logic” of the law before us, Beach Communica- tions, 508 U. S., at 313, but only to ensure that it does not violate the equal protection guarantee of the Fourteenth Amendment. Having concluded it does not, we leave ques- tions regarding its policy to the people, their elected repre- sentatives, and the democratic process. 526 UNITED STATES v. SKRMETTI

Thomas, J., concurring

The judgment of the United States Court of Appeals for the Sixth Circuit is affrmed. It is so ordered. Justice Thomas, concurring. A Tennessee law prevents children from receiving certain medical interventions if administered to treat gender dys- phoria. See Prohibition on Medical Procedures Performed on Minors Related to Sexual Identity, S. B. 1, 113th Gen. Assem., 1st Extra. Sess.; Tenn. Code Ann. § 68–33–101 et seq. (2023) (SB1). The United States and private plaintiffs chal- lenged the law on Equal Protection Clause grounds, arguing that it discriminates based on sex and fails heightened scru- tiny. Today, the Court correctly concludes that SB1 does not classify on the basis of sex and thus is subject only to rational-basis review. I join the Court's opinion in full. I write separately to address some additional arguments made in defense of Tennessee's law. Page Proof Pending I Publication Before this Court, the United States and the private plain- tiffs asserted that, under the reasoning of Bostock v. Clayton County, 590 U. S. 644 (2020), SB1 discriminates on the basis of sex. See Brief for United States 22, 27–28; 1 Brief for Re- spondents in Support of Petitioner 18, 24–25. In Bostock, the Court held that, in the context of Title VII of the Civil Rights Act of 1964, “homosexuality and transgender status are inextricably bound up with sex,” such that discriminat- ing on the basis of either characteristic amounts to discrimi- nation “because of ” sex under that statute. 590 U. S., at 660–661, 665. The United States and the private plaintiffs have argued that Bostock's “fundamental insight about the nature of sex discrimination applies in the equal-protection 1 The United States changed its position following oral argument, but it neither withdrew its briefs nor sought to dismiss the case. Cite as: 605 U. S. 495 (2025) 527

context” too. Brief for United States 27. I would reject that argument for several reasons. While I continue to think that the Bostock majority's logic “fails on its own terms,” see 590 U. S., at 689–699 (Alito, J., dissenting), I see in any event no reason to import Bostock's Title VII analysis into the Equal Protection Clause. The Bostock Court recognized that “other federal . . . laws that prohibit sex discrimination” were not before it, id., at 681 (majority opinion), and thus rested its analysis on what it took to be the ordinary meaning of the relevant statutory terms—“ `because of, ' ” “ `otherwise . . . discriminate against,' ” and “individual”—within the context of Title VII, id., at 656–659; see 42 U. S. C. § 2000e–2(a)(1). The Equal Protection Clause includes none of this lan- guage. See Amdt. 14, § 1 (“No State shall . . . deny to any person within its jurisdiction the equal protection of the laws”). “That such differently worded provisions should mean the same thing is implausible on its face.” Students for Fair Admissions, Inc. v. President and Fellows of Har- vard College, 600 U. S. 181, 308 (2023) (Gorsuch, J., concur- ring); cf. Department of Ed. v. Louisiana, 603 U. S. 866, 867 (2024) (per curiam) (unanimously holding that “preliminary injunctive relief ” was warranted to enjoin a rule extending Bostock's reasoning to Title IX of the Education Amend- ments of 1972).2

2 Justice Sotomayor acknowledges that “the Equal Protection Clause and Title VII use different words,” but deems this an irrelevant “differ- ence in wording” because the Court's equal protection precedents and Title VII both prohibit sex discrimination. Post, at 591, n. 9 (dissenting opinion). An abstract similarity between the purposes of the Constitu- tion and a statute is not a license to import the statute's interpretation into the Constitution, much less to ignore the Constitution's text. Accord, e. g., A. Scalia, A Matter of Interpretation 38 (1997) (“What I look for in the Constitution is precisely what I look for in a statute: the original mean- ing of the text”). 528 UNITED STATES v. SKRMETTI

Extending the Bostock framework here would depart dra- matically from this Court's Equal Protection Clause juris- prudence. We have faced sexual-orientation claims in the equal protection context for decades. See, e. g., Obergefell v. Hodges, 576 U. S. 644 (2015); United States v. Windsor, 570 U. S. 744 (2013); Romer v. Evans, 517 U. S. 620 (1996). “But in those cases, the Court never suggested that sexual orien- tation discrimination is just a form of sex discrimination” warranting heightened constitutional scrutiny. Bostock, 590 U. S., at 797 (Kavanaugh, J., dissenting). For example, while pregnancy is undeniably “bound up with sex,” id., at 661 (majority opinion), the Court has rejected the contention that the exclusion of pregnancy-related conditions from dis- ability benefts violates the Equal Protection Clause, see Geduldig v. Aiello, 417 U. S. 484, 494 (1974); see also Dobbs v. Jackson Women's Health Organization, 597 U. S. 215, 236 (2022) (“[T]he regulation of a medical procedure that only one sex can undergo does not trigger heightened constitu- tional scrutiny”). Applying Bostock's reasoning to the Equal Protection Clause would also invite sweeping consequences. Many statutes “regulate medical procedures defined by sex.” L. W. v. Skrmetti, 83 F. 4th 460, 482 (CA6 2023) (collecting examples, including laws referencing testicular and prostate cancer). If heightened scrutiny applied to such laws, then “[a]ny person with standing to challenge” such a decision could “haul the State into federal court and compel it to es- tablish by evidence (presumably in the form of expert testi- mony) that there is an `exceedingly persuasive justifcation' for the classifcation.” United States v. Virginia, 518 U. S. 515, 597 (1996) (Scalia, J., dissenting). Given the ensuing po- tential for “high-cost, high-risk lawsuit[s],” ibid., States might simply decline to adopt or enforce sex-based medical laws or regulations, even where such rules would be best medical practice. The burden of skeptical judicial review is therefore far from the “modest step” of requiring a State to Cite as: 605 U. S. 495 (2025) 529

“show its work” that the dissent posits. Post, at 607 (opin- ion of Sotomayor, J.).3 And, if Bostock's reasoning applies to sex, it is diffcult to see why it would not apply to other protected characteristics. Race presumably would be a but-for cause of—or, at least, “inextricably bound up with,” 590 U. S., at 660–661—a uni- versity's decision to credit “an applicant's discussion of how race affected his or her life,” Students for Fair Admissions, Inc., 600 U. S., at 230. Under Bostock's reasoning, such an essay is permissible only if it can survive our “daunting” strict-scrutiny standard. 600 U. S., at 206; but see, e. g., Washington v. Davis, 426 U. S. 229, 239 (1976) (noting that the Court has “never held that the constitutional standard for adjudicating claims of invidious racial discrimination is identical to the standards applicable under Title VII”). The Constitution compels none of this. While the major- ity concludes that SB1 does not discriminate based on sex even under Bostock's incorrect reasoning, see ante, at 519– 520, I would make clear that, in constitutional challenges, courts need not engage Bostock at all.

II The Court rightly rejects efforts by the United States and the private plaintiffs to accord outsized credit to claims about medical consensus and expertise. The United States as- serted that “the medical community and the nation's leading 3 I assume for purposes of this opinion that government-sponsored sex discrimination triggers heightened scrutiny under the Equal Protection Clause. As I have noted elsewhere, however, “[i]t is possible that the Equal Protection Clause does not prohibit discriminatory legislative classi- fcations” at all. United States v. Vaello Madero, 596 U. S. 159, 178, n. 4 (2022) (concurring opinion). And, even if it does, the Court “routinely applied rational-basis review” to sex-discrimination claims “until the 1970's,” Virginia, 518 U. S., at 575 (Scalia, J., dissenting), which might suggest that the application of heightened scrutiny to such claims is a departure from the Fourteenth Amendment's original understanding. But, the parties have not briefed the issue, so I do not pass upon it here. 530 UNITED STATES v. SKRMETTI

hospitals overwhelmingly agree” with the Government's po- sition that the treatments outlawed by SB1 can be medically necessary. Brief for United States 35; see also Brief for Re- spondents in Support of Petitioner 5 (asserting that “[e]very major medical association in the United States” supports this position). The implication of these arguments is that courts should defer to so-called expert consensus. There are several problems with appealing and deferring to the authority of the expert class. First, so-called experts have no license to countermand the “wisdom, fairness, or logic of legislative choices.” FCC v. Beach Communica- tions, Inc., 508 U. S. 307, 313 (1993). Second, contrary to the representations of the United States and the private plaintiffs, there is no medical consensus on how best to treat gender dysphoria in children. Third, notwithstanding the alleged experts' view that young children can provide in- formed consent to irreversible sex-transition treatments, whether such consent is possible is a question of medical eth- ics that States must decide for themselves. Fourth, there are particularly good reasons to question the expert class here, as recent revelations suggest that leading voices in this area have relied on questionable evidence, and have allowed ideology to infuence their medical guidance. Taken together, this case serves as a useful reminder that the American people and their representatives are entitled to disagree with those who hold themselves out as experts, and that courts may not “sit as a super-legislature to weigh the wisdom of legislation.” Day-Brite Lighting, Inc. v. Mis- souri, 342 U. S. 421, 423 (1952). By correctly concluding that SB1 warrants the “paradigm of judicial restraint,” Beach Communications, 508 U. S., at 314, the Court re- serves to the people of Tennessee the right to decide for themselves. A The views of self-proclaimed experts do not “shed light on the meaning of the Constitution.” Dobbs, 597 U. S., at 272– Cite as: 605 U. S. 495 (2025) 531

273. Thus, whether “major medical organizations” agree with the result of Tennessee's democratic process is irrele- vant. Post, at 582, n. 5 (opinion of Sotomayor, J.). To hold otherwise would permit elite sentiment to distort and stife democratic debate under the guise of scientifc judgment, and would reduce judges to mere “spectators . . . in construing our Constitution.” 83 F. 4th, at 479. Just a few Terms ago, this Court acknowledged the impor- tance of reserving to the democratic process the right to decide controversial medical questions. In Dobbs, the re- spondents sought to invoke the authority of “overwhelming medical consensus” and “numerous major medical organiza- tions” to dispatch with Mississippi's asserted interest in min- imizing pain for the unborn. Brief for Respondents, O. T. 2021, No. 19–1932, pp. 31–32. The Court pointedly rejected the notion that a consensus among popular expert groups could remove “the mitigation of fetal pain” from the “legiti- mate interests” of the people. 597 U. S., at 301. Rational-basis review is critical to safeguarding these le- gitimate interests. Under this level of review, courts ask only whether a law is “rationally related to a legitimate gov- ernmental interest.” Department of Agriculture v. Mo- reno, 413 U. S. 528, 533 (1973). That deferential standard is not only legally compelled in this case, but is practically es- sential for preserving “the original constitutional proposition that courts do not substitute their social and economic beliefs for the judgment of legislative bodies. ” Ferguson v. Skrupa, 372 U. S. 726, 730 (1963). When legislation does not cross constitutional lines, States must have leeway to effect the judgment of their citizens—no matter whether experts disagree. And, when this Court has nonetheless given ex- alted status to expert opinion, it has been to our detriment: Past deference to expertise provided the theory of eugenics “added legitimacy and considerable momentum,” with “[t]his Court thr[owing] its prestige behind the eugenics movement in its 1927 decision upholding the constitutionality of Virgin- 532 UNITED STATES v. SKRMETTI

ia's forced-sterilization law.” Box v. Planned Parenthood of Ind. and Ky., Inc., 587 U. S. 490, 499–500 (2019) (Thomas, J., concurring) (citing Buck v. Bell, 274 U. S. 200 (1927)). For- tunately, we do not repeat that mistake today.

B Before this Court, the United States asserted that “over- whelming evidence” supports the use of puberty blockers and cross-sex hormones for treating pediatric gender dys- phoria, and that this view represents “the overwhelming consensus of the medical community.” Pet. for Cert. 2, 7. These claims are untenable. “[T]he concept of gender dys- phoria as a medical condition is relatively new and the use of drug treatments that change or modify a child's sex char- acteristics is even more recent.” 83 F. 4th, at 472. The treatments at issue are subject to a rapidly evolving debate that demonstrates a lack of medical consensus over their risks and benefts. Under these conditions, it is imperative that courts treat state legislation with “a strong presumption of validity,” Beach Communications, 508 U. S., at 314, and in turn protect States' ability to enact “high-stakes medical policies, in which compassion for the child points in both di- rections,” 83 F. 4th, at 472. 1 SB1 prohibits puberty blockers, cross-sex hormones, and surgery for the purpose of treating gender dysphoria in chil- dren. See Tenn. Code Ann. §§ 68–33–102(5)(A)–(B), 68–33– 103(a). The United States and the dissent have described these medications and procedures as “gender-affirming care.” Brief for United States 2; post, at 581 (opinion of So- tomayor, J.). But, that “sanitized description” obscures the nature of the medical interventions at issue. Stenberg v. Carhart, 530 U. S. 914, 983 (2000) (Thomas, J., dissenting). I therefore begin with an overview of the treatments regu- lated under SB1. Cite as: 605 U. S. 495 (2025) 533

Puberty Blockers. Puberty blockers are powerful syn- thetic drugs “designed to slow the development of male and female physical features.” 83 F. 4th, at 467. The Food and Drug Administration (FDA) initially approved these drugs “to treat prostate cancer; endometriosis, a painful disease that causes uterine tissue to grow elsewhere in the body; and the unusually early onset of puberty,” also known as “precocious puberty.” M. Twohey & C. Jewett, Pressing Pause on Puberty, N. Y. Times, Nov. 14, 2022, pp. A14–A15 (Twohey 2022). For purposes of treating gender dysphoria, however, pu- berty blockers generally are administered “off-label,” mean- ing without FDA authorization for the specifc use. See 2 App. 838–839; 83 F. 4th, at 478. Although it is neither un- usual nor unlawful for drugs to be used off-label, the FDA has recognized that “just because a drug has been approved for one class of patients doesn't mean it's safe for another.” Twohey 2022, at A15. That admonition is important here: To treat precocious puberty, puberty blockers are adminis- tered until the age appropriate for puberty; to treat gender dysphoria, however, puberty blockers are administered to stop puberty throughout the years it would normally occur. See 2 App. 677. The “use of drugs to suppress normal pu- berty has multiple organ system effects whose long-term consequences have not been investigated.” Ibid. This absence of evidence is a “major drawback” in assess- ing the effects of puberty blockers on children with gender dysphoria. G. Betsi, P. Goulia, S. Sandhu, & P. Xekouki, Pu- berty Suppression in Adolescents With Gender Dysphoria: An Emerging Issue With Multiple Implications, Frontiers in Endocrinology 16 (2024). “The existing studies are limited in number, of small sample size, uncontrolled, observational, usually short-term, [and] potentially subject to bias.” Ibid.; see also, e. g., C. Terhune, R. Respaut, & M. Conlin, As More Transgender Children Seek Medical Care, Families Confront Many Unknowns, Reuters (Oct. 6, 2022), https://www. 534 UNITED STATES v. SKRMETTI

reuters.com/investigates/special-report/usa-transyouth-care (“No clinical trials have established [puberty blockers'] safety for such off-label use”). It is undisputed, however, that these treatments carry risks. Research suggests that, aside from interrupting a child's normal pubertal development, puberty blockers may lead to decreased bone density and impacts on brain develop- ment. See, e. g., 2 App. 678–680; M. Cretella, Gender Dys- phoria in Children, 32 Issues in L. & Med. 287, 297 (2017). And, “[d]espite widespread assertions that puberty blockers are `fully reversible,' ” it is unclear whether “patients ever develop normal levels of fertility if puberty blockers are ter- minated after a `prolonged delay of puberty.' ” 2 App. 678. At bottom, “[t]here remains considerable uncertainty regard- ing the effects of puberty blockers in individuals experienc- ing” gender dysphoria. A. Miroshnychenko et al., Puberty Blockers for Gender Dysphoria in Youth: A Systematic Re- view and Meta-Analysis, Online First, Archives of Disease in Childhood (Jan. 24, 2025) (draft, at 1), https://adc.bmj.com/ content/110/6/429.4 Cross-sex hormones. Following puberty blockers, the next stage of sex-transition treatments for children involves cross-sex hormones. This treatment is also typically “off- label,” 2 App. 780, and requires “very high doses” of hor- mones of the opposite sex, id., at 769. For example, one of the organizations that sets standards for pediatric sex- transition treatment recommends raising transitioning fe- males' levels of testosterone “6 to 100 times higher than na-

4 While the United States addressed the risks of puberty blockers “in and of themselves,” Tr. of Oral Arg. 46, the vast majority of gender dys- phoric children treated with puberty blockers progress to cross-sex- hormone treatment. See, e. g., 2 App. 554 (citing study in which “98% of those who started puberty suppression progressed to cross-sex hormone therapy”). A discussion of puberty blockers' risks therefore should not exclude the risks presented by cross-sex hormones. Cite as: 605 U. S. 495 (2025) 535

tive female testosterone levels.” Id., at 774. For males seeking to transition into females, the organization recom- mends raising levels of estradiol, a type of estrogen, to “2 to 43 times above the normal range.” Id., at 780. Prescribing such high doses of testosterone to girls in- duces “hyperandrogenism,” which can cause increased car- diovascular risk, “irreversible changes to the vocal cords,” “clitoromegaly and atrophy of the lining of the uterus and vagina,” as well as “ovarian and breast cancer.” Id., at 772– 779. Giving high doses of estrogen to boys induces “hyper- estrogenemia,” which can produce similarly severe side ef- fects including, among other things, increased cardiovascular risk, breast cancer, and sexual dysfunction. Id., at 779–781. And, for girls and boys alike, “it is generally accepted, even by advocates of transgender hormone therapy, that hormonal treatment impairs fertility, which may be irreversible.” Id., at 520–521; accord, W. Hembree et al., Endocrine Treatment of Gender-Dysphoric/Gender-Incongruent Persons: An En- docrine Society Clinical Practice Guideline, 102 J. Clinical Endocrinology & Metabolism 3869, 3882 (2017) (ES Guidelines). Surgery. SB1 also bans “[s]urgically removing, modify- ing, altering, or entering into tissues, cavities, or organs” as a treatment for gender dysphoria. Tenn. Code Ann. § 68– 33–102(5)(A). The District Court concluded that the plain- tiffs lacked standing to challenge SB1's ban on sex-transition surgery for minors, see ante, at 508, and the parties do not address this provision's constitutionality here. But, the United States has taken the position that “surgery is essen- tial and medically necessary to alleviate gender dysphoria.” Amended Complaint in Intervention in Boe v. Marshall, No. 2:22–cv–00184 (MD Ala., May 4, 2022), ECF Doc. 92, p. 9, ¶39. The practice therefore warrants brief discussion. Sex-transitioning surgeries for girls include “the surgical removal of the breasts” and “phalloplasty,” that is, an “at- 536 UNITED STATES v. SKRMETTI

temp[t] to create a pseudo-penis” by transplanting “a roll of skin and subcutaneous tissue” from another area of the body “to the pelvis.” 2 App. 784–785; see also Lange v. Houston Cty., 101 F. 4th 793, 802 (CA11) (Brasher, J., dissenting) (“[A] natal woman's phalloplasty `involves removal of the uterus, ovaries, and vagina, and creation of a neophallu[s] and scro- tum with scrotal prostheses,' which `is a multistage recon- structive procedure' ”), vacated and reh'g en banc granted, 110 F. 4th 1254 (CA11 2024). For boys, surgical interven- tions include “removal of the testicles alone to permanently lower testosterone levels,” as well as an “attempt to create a pseudo-vagina” by “surgically open[ing]” the boy's penis, removing “erectile tissue,” and then “clos[ing] and invert[ing the penis] into a newly created cavity in order to simulate a vagina.” 2 App. 784. These surgical interventions are irreversible, entail signifcant complications, and, in some cases, result in permanent infertility. Id., at 782–786; see also ES Guidelines 3893. 2 The ongoing debate over the efficacy of sex-transition treatments for children confrms that medical and regulatory authorities are not of one mind about the treatments' risks and benefts. These conditions illustrate why States may rightly be skeptical of groups or advocates claiming that ex- pert consensus supports their position, and why courts must exercise restraint in reviewing state legislatures' decisions in this area. Accord, e. g., Beach Communications, 508 U. S., at 314. The treatments now referred to as “gender-affrming care” were “not available for minors until just before the millen- nium.” 83 F. 4th, at 467. These treatments originated with Dutch healthcare workers in the 1990s, who frst “began using puberty blockers . . . to treat gender dysphoria in mi- nors.” Ibid. The so-called “Dutch Protocol” “permitted puberty blockers for minors during the early stages of pu- Cite as: 605 U. S. 495 (2025) 537

berty, allowed hormone therapy at 16, and allowed genital surgery at 18.” Ibid. (internal quotation marks omitted). In 1998, the World Professional Association for Transgen- der Health (WPATH)—which is regarded by some as “the leading association of medical professionals treating trans- gender individuals,” Brief for United States 3—revised its treatment standards to “endorse the Dutch Protocol.” 83 F. 4th, at 467. Originally, WPATH's guidelines permitted puberty blockers at the onset of puberty, cross-sex hormones for those 16 or older, and sex-change surgery only for adults. Ibid. WPATH relaxed its recommendations in 2012, and began permitting cross-sex hormones for children under the age of 16. Ibid. WPATH further relaxed its recommenda- tions when it published the eighth (and current) version of its standards of care in 2022. See E. Coleman et al., Stand- ards of Care for the Health of Transgender and Gender Di- verse People, Version 8, 23 Int'l J. Transgender Health (2022) (WPATH 2022 Guidelines or Guidelines). These Guidelines endorse using puberty blockers and cross-sex hormones at the onset of puberty and allowing children to receive many surgical treatments previously reserved for adults. See id., at S64–S66. “On the whole, the standards of care for minors `have become less restrictive over the course of time.' ” 83 F. 4th, at 468. At the same time, the number of children identifying as transgender has surged, and medical professionals have in- creasingly expressed doubts over the quality of evidence supporting the use of puberty blockers, cross-sex hormones, and surgery to treat them. See ante, at 504–505. Over the past several years, public health authorities in different coun- tries have concluded that these sex-transition treatments are experimental in practice, and that the evidence supporting their use is of “ `very low certainty,' ” “ `insuffcient,' ” and “ `in- conclusive.' ” Ante, at 505. “In countries like Sweden, Nor- way, France, the Netherlands and Britain—long considered 538 UNITED STATES v. SKRMETTI

exemplars of gender progress—medical professionals have recognized that early research on medical interventions for childhood gender dysphoria was either faulty or incomplete.” P. Paul, Gender Dysphoric Kids Deserve Better Care, N. Y. Times, Feb. 4, 2024, p. 9 (Paul 2024); accord, Tenn. Code Ann. § 68–33–101(e) (“The legislature fnds that health authorities in Sweden, Finland, and the United Kingdom . . . have found no evidence that the benefts of these procedures outweigh the risks”); 1 App. 332–342 (describing countries' skepticism over the use of puberty blockers and cross-sex hormones as treatments).5

5 Justice Sotomayor suggests that the restrictions on gender- dysphoria treatments imposed in Norway, Sweden, and England are inap- posite because those countries still permit some treatments where “medi- cally necessary,” whereas Tennessee's SB1 does not. Post, at 582, n. 4 (dissenting opinion). But, States might reasonably question whether any of the banned treatments are “medically necessary,” as the supposed ex- perts in the feld have adopted an exceptionally broad understanding of that concept. Consider the Guidelines' chapter on “those who identify as eunuchs,” a group that includes “individuals . . . assigned male at birth” who “wish to eliminate masculine physical features, masculine genitals, or genital functioning.” WPATH 2022 Guidelines S88. During a deposition, an author of the Guidelines confrmed that “WPATH's offcial position” is that castration may be “medically necessary” even where a male who iden- tifes as a eunuch and seeks castration has “no recognized mental health conditions” and where “no fnding is made that he's actually at high risk of self-castration.” Boe v. Marshall, No. 2:22–cv–00184 (MD Ala., Oct. 9, 2024), ECF Doc. 700–3, p. 52. This expansive understanding of medical necessity would seem to justify any medical intervention so long as it might help individuals “better align their bodies with their gender iden- tity,” WPATH 2022 Guidelines S88, and presumably animates WPATH's conclusion that surgical interventions can constitute “medically necessary gender-affrming medical treatment[s] in adolescents,” id., at S66. Given that the limits of “medical necessity” in this context are debatable, States might reasonably decline to provide exceptions for it—particularly where, as here, they have reached the conclusion that specifc procedures for chil- dren are “experimental in nature” and may carry unknown “harmful ef- fects.” Tenn. Code Ann. § 68–33–101(b). Cite as: 605 U. S. 495 (2025) 539

The Cass Review, published in April 2024, offers an infu- ential example of the degree to which the debate over pediat- ric sex-transition treatments remains unsettled. See H. Cass, Independent Review of Gender Identity Services for Children and Young People: Final Report (Cass Review). After witnessing a 40-fold increase in the number of refer- rals to its centralized clinic for sex-transitioning services, the United Kingdom's National Health Service (NHS) commis- sioned this report to conduct a “thorough independent re- view of the use of puberty blockers and cross-sex hormones” to treat children with gender dysphoria. 1 App. 333–334. The report concludes that “we have no good evidence on the long-term outcomes of interventions to manage gender- related distress,” and highlights the lack of reliable evidence to support the use of puberty blockers and cross-sex hor- mones in treating transgender kids. Cass Review 13, 32–33 (observing “insuffcient/inconsistent evidence about the ef- fects of puberty suppression,” and “ `a lack of high-quality research assessing the outcomes of hormone interventions in adolescents with gender dysphoria/incongruence' ”); see also ante, at 524–525. Among other things, the Cass Review de- termined that the “evidence [the researchers] found did not support th[e] conclusion” that “hormone treatment reduces the elevated risk of death by suicide” among children suffer- ing from gender dysphoria. Cass Review 33; see also id., at 187 (“[T]he evidence does not adequately support the claim that gender-affrming treatment reduces suicide risk”). This shifting scientifc landscape has forced governments to act quickly under conditions of uncertainty. In the months following the Cass Review's publication, for example, NHS imposed new restrictions on the use of puberty block- ers and cross-sex hormones for sex-transition treatments. See ante, at 525. And, just a week after oral argument in this case, the United Kingdom indefnitely banned new pre- scriptions of puberty blockers to treat children with gender 540 UNITED STATES v. SKRMETTI

dysphoria, except in clinical trials. See S. Castle, Ban on Puberty Blockers for U. K. Teens Is Settled, N. Y. Times Int'l, Dec. 13, 2024, p. A11. In areas with this much “medi- cal and scientifc uncertainty,” courts must afford States “wide discretion.” Gonzales v. Carhart, 550 U. S. 124, 163 (2007). C Setting aside whether sex-transition treatments for chil- dren are effective, States may legitimately question whether they are ethical. States have a legitimate interest “in pro- tecting the integrity and ethics of the medical profession.” Washington v. Glucksberg, 521 U. S. 702, 731 (1997). And, as the United States has acknowledged, “the `general ethical principles' governing pediatric care” require the patient's in- formed consent. Brief for United States 5. Mounting evi- dence gives States reason to question whether children are capable of providing informed consent to irreversible sex- transition treatments, and thus whether these treatments can be ethically administered.

1 States could reasonably conclude that the level of young children's cognitive and emotional development inhibits their ability to consent to sex-transition treatments. Consistent with WPATH's recommendation that puberty blockers be available from the onset of puberty, see WPATH 2022 Guide- lines S111, S256, “[m]any physicians in the United States and elsewhere” now “prescrib[e] blockers to patients at the frst stage of puberty—as early as age 8.” Twohey 2022, at A14. There is no dispute, however, that the “decision-making capacity” of adolescents “is developing, but not yet com- plete.” 2 App. 895. This Court has recognized as much in other contexts, explaining that children's “lack of maturity” and “underdeveloped sense of responsibility” often lead to “impetuous and ill-considered actions and decisions. ” Cite as: 605 U. S. 495 (2025) 541

Roper v. Simmons, 543 U. S. 551, 569 (2005) (internal quota- tion marks omitted). It is therefore unsurprising that “[t]he risks associated with puberty blockers and cross-sex hor- mones are diffcult for adolescents to comprehend and ap- preciate,” as the “near certainty of infertility . . . is likely to not be appreciated until the age during which most individu- als consider having children.” 2 App. 894. But, these are precisely the risks to which children who receive these treatments are required to consent. Consider the contents of a consent form obtained from a gender clinic in Alabama. After providing a long list of potential risks and side effects, many of which are discussed above, see supra, at 533–535 the form requires both the child and par- ent to initial their consent to various statements. Among these are acknowledgments that “the side effects and safety of these medicines are not completely known,” that the pro- posed treatment “may affect my sex life in different ways and future ability to cause a pregnancy,” and that the treat- ments may lead to permanent infertility. Boe, ECF Doc. 78–41, pp. 3–4, 10. The capacity to knowingly consent to these medical interventions requires a level of comprehen- sion about science, sex, and fertility that state legislatures could determine a child is unlikely to possess. See 2 App. 893–895; Tenn. Code Ann. § 68–33–101(h) (fnding that “mi- nors lack the maturity to fully understand and appreciate the life-altering consequences” of the treatments at issue).6 6 Parents also may have diffculty providing informed consent to their children's sex-transition treatments. Reports suggest that, in medical consultations, “[p]arents are routinely warned that to pursue any path outside of agreeing with a child's self-declared gender identity is to put a gender dysphoric youth at risk for suicide, which feels to many people like emotional blackmail.” Paul 2024, at 8; see also Eknes-Tucker v. Governor of Ala., 114 F. 4th 1241, 1268 (CA11 2024) (Lagoa, J., concurring in denial of rehearing en banc) (acknowledging “testimony from nine parents who said that doctors, therapists, and other practitioners pressured them to start their children on cross-sex hormones and puberty blockers or other- 542 UNITED STATES v. SKRMETTI

2 The voices of “detransitioners”—individuals who have un- dergone sex-transition treatments but no longer view them- selves as transgender—provide States with an additional reason to question whether children are providing informed consent to the medical interventions described above. See, e. g., Brief for Larger Detransitioners Community et al. as Amici Curiae 24–28; Brief for Partners for Ethical Care et al. as Amici Curiae 17–38. A recurring theme in discussions of detransitioners is that doctors have responded to the “skyrocketing” “number of adolescents requesting [sex-transitioning] medical care” by “hastily dispensing medicine or recommending medical doc- tors prescribe it.” L. Edwards-Leeper & E. Anderson, The Mental Health Establishment Is Failing Trans Kids, Wash- ington Post, Nov. 28, 2021, pp. B1–B2. In many cases, evi- dence suggests that children “are being rushed toward” med- ical treatment “[w]ithout proper assessment,” and “the rising number of detransitioners that clinicians report seeing . . . indicates that this approach can backfre.” Id., at B2; ac- cord, e. g., Eknes-Tucker v. Governor of Ala., 114 F. 4th 1241, 1267 (CA11 2024) (opinion of Lagoa, J.) (“Alabama presented evidence from many detransitioners who uniformly testifed that they were not aware of the long-term impacts of the treatments they underwent”); Brief for Respondents 12–13 (explaining that, before enacting SB1, the Tennessee Legisla- ture heard testimony “from a detransitioner who explained that she was not `capable of making informed lifelong deci- sions' as a teenager” but nevertheless received transition treatments).7

wise circumvented their wishes”). States might reasonably question whether, under such conditions, parents' consent is valid and consistent with ethical principles. 7 The United States has asserted that “all of the available evidence shows that” detransitioners constitute “a very small number” of individu- als receiving sex-transition treatments. Tr. of Oral Arg. 49. But, “those Cite as: 605 U. S. 495 (2025) 543

States have an interest in ensuring that minor patients have the time and capacity to fully understand the irrevers- ible treatments they may undergo. Cf. Gonzales, 550 U. S., at 159 (identifying State's “legitimate concern” regarding “lack of information” provided by abortionists). And, de- spite the supposed expert consensus that young children can consent to irreversible sex-transition treatments, States have good reasons to disagree; as “any parent knows,” chil- dren's comprehension is limited, Roper, 543 U. S., at 569, and the growing number of detransitioners illustrates the risks of assuming otherwise. D Recent revelations suggest that WPATH, long considered a standard bearer in treating pediatric gender dysphoria, see Brief for United States 3, bases its guidance on insuffcient evidence and allows politics to infuence its medical conclu- sions. Beyond the lack of consensus over the effcacy and ethics of pediatric sex-transition treatments, these develop- ments provide States even stronger bases for treating sup- posed authorities in this area with skepticism. WPATH itself recognizes that evidence supporting the ef- fcacy of puberty blockers, cross-sex hormones, and surgical intervention for treating gender dysphoria in children is

who abandon a transition are likely to stop talking to their doctors, and so disappear from the fgures.” Trans Substantiation, The Economist, Apr. 8, 2023, p. 18; see also 2 App. 653 (“A signifcant majority (76%) [of detransitioners in one study] did not inform their clinicians of their detran- sition”). Thus, “[t]he number of people who detransition or discontinue gender treatments is not precisely known.” A. Ghorayshi, Youth Gender Clinic Lands in a Political Storm, N. Y. Times, Aug. 26, 2023, p. A12. And, because “[i]t is quite possible that low reported rates of detransition and regret” among earlier groups of patients “will no longer apply” to the increasingly large number of children seeking these treatments, “there is reason to believe that that the numbers of detransitioners may increase.” M. Irwig, Detransition Among Transgender and Gender-Diverse People— An Increasing and Increasingly Complex Phenomenon, 107 J. Clinical En- docrinology & Metabolism e4261, e4262 (2022). 544 UNITED STATES v. SKRMETTI

lacking. In its most recent Guidelines, for example, the group notes that “[a] key challenge in adolescent transgender care is the quality of evidence evaluating the effectiveness of medically necessary gender-affrming medical and surgical treatments . . . over time.” WPATH 2022 Guidelines S45– S46 (emphasis added). A contributor to the Guidelines un- derscored this challenge, explaining that, “ `[o]ur concerns, echoed by the social justice lawyers we spoke with, is that evidence-based review reveals little or no evidence and puts us in an untenable position in terms of affecting policy or winning lawsuits.' ” Eknes-Tucker, 114 F. 4th, at 1261 (opin- ion of Lagoa, J.). Nevertheless, WPATH publicly represents that “[g]ender- affrming interventions are based on decades of clinical ex- perience and research,” and are “safe and effective” treat- ments. Guidelines S18. WPATH appears to rest this conclusion on self-referencing consensus rather than evidence-based research, which may help explain the group's confdence in the face of concededly inadequate evidence. See Cass Review 130. In its analysis of several “guidelines” for transgender medicine—including not only the WPATH 2022 Guidelines, but also those from groups like the Endo- crine Society—the Cass Review notes that “most of the guidelines described insuffcient evidence about the risks and benefts of medical treatment in adolescents,” but neverthe- less “went on to cite this same evidence to recommend medi- cal treatments,” or to base their recommendations on “other guidelines” prescribing the same course of action. Ibid. (emphasis added). This approach was particularly pro- nounced in the WPATH 2022 Guidelines, which “cited many of the other national and regional guidelines to support some of its recommendations, despite these guidelines having been considerably infuenced by WPATH 7,” the prior version of WPATH's Standards of Care. Cass Review 130. States would also have good reason to question whether WPATH has a basis for believing that children can provide Cite as: 605 U. S. 495 (2025) 545

informed consent to sex-transition treatments. “[I]n a leaked recording of a WPATH Panel,” for example, an endo- crinologist acknowledged the diffculty of explaining cross- sex hormones and puberty blockers to children, noting that “ `the thing you have to remember about kids is that we're often explaining these sorts of things to people who haven't even had biology in high school yet.' ” Eknes-Tucker, 114 F. 4th, at 1268–1269 (opinion of Lagoa, J.). “ `[I]t's always a good theory that you talk about fertility preservation with a 14 year old,' ” the endocrinologist continued, “ `but I know I'm talking to a blank wall.' ” Id., at 1269. Analogizing a teenage patient's comprehension to that of a blank wall should raise serious concerns regarding the patient's ability to provide informed consent. Given WPATH's recognition that “[c]onsent requires the cognitive capacity to understand the risks and benefts of a treatment,” Guidelines S38, States thus might reasonably question whether WPATH could be “genuine in its claim that these treatments are safe, effec- tive, and well understood, particularly for minors,” Eknes- Tucker, 114 F. 4th, at 1268 (opinion of Lagoa, J.). Other “recent revelations” might reinforce the conclusion that “WPATH's lodestar is ideology, not science.” Id., at 1261. For example, newly released documents suggest that WPATH tailored its Standards of Care in part to achieve legal and political objectives. In one instance, the chair of WPATH's guidelines committee testifed that it was “ethi- cally justifable” for the authors of the WPATH 2022 Guide- lines to “advocate for language changes [in these Guidelines] to strengthen [their] position in court.” Boe, ECF Doc. 700– 3, p. 42. One of the Guidelines' contributors was more di- rect: “My hope with these [Guidelines] is that they land in such a way as to have serious effect in . . . law and pol- icy settings.” ECF Doc. 700–13, p. 25; see also Brief for State of Alabama as Amicus Curiae 11–15 (Alabama Brief) (describing similar statements from other WPATH contributors). 546 UNITED STATES v. SKRMETTI

Worse, recent reporting has exposed that WPATH chan- ged its medical guidance to accommodate external political pressure. See Brief for Respondents 9–11; Alabama Brief 15–23. Unsealed documents reveal that a senior offcial in the Biden administration “pressed [WPATH] to remove age limits for adolescent surgeries from guidelines for care of transgender minors” on the theory that “ `specifc listings of ages, under 18, will result in devastating legislation for trans care.” A. Ghorayshi, Biden Offcials Pushed To Remove Age Limits for Transgender Surgery, N. Y. Times, June 27, 2024, p. A17. Despite some internal disagreement, WPATH acceded and “removed the age minimums in its eighth edition of the standards of care.” Ibid.; see Alabama Brief 17–20.8 Over a decade ago, one of WPATH's contributors explained that “ `WPATH aspires to be both a scientifc organization and an advocacy group for the transgendered,' ” and ad- mitted that WPATH's Standards of Care “ `is not a politically neutral document.' ” Kosilek v. Spencer, 774 F. 3d 63, 78 (CA1 2014). WPATH's apparent willingness to let political interests infuence its medical conclusions highlights this re- ality. States are never required to substitute expert opinion for their legislative judgment, and, when the experts appear to have compromised their credibility, it makes good sense to chart a different course.9

8 After its infuence became public, the Government backtracked and announced that it “opposed gender-affrming surgery for minors.” R. Rabin, T. Rosenbluth, & N. Weiland, Biden Opposes Surgery for Transgen- der Minors, N. Y. Times, June 30, 2024, p. 22. 9 WPATH's deference to political pressure is not the only high-profle example of ideology infuencing medical conclusions in this area. Re- cently, “[a]n infuential doctor and advocate of adolescent gender treat- ments” declined to publish “a long-awaited study of puberty-blocking drugs” that suggested her initial hypothesis about the drugs' effcacy had not “borne out.” A. Ghorayshi, Doctor, Fearing Outrage, Slows a Gender Study, N. Y. Times, Oct. 24, 2024, pp. A1, A23. The doctor explained that she feared “the fndings might fuel the kind of political attacks that have Cite as: 605 U. S. 495 (2025) 547

Barrett, J., concurring

* * * This case carries a simple lesson: In politically contentious debates over matters shrouded in scientifc uncertainty, courts should not assume that self-described experts are correct. Deference to legislatures, not experts, is particularly criti- cal here. Many prominent medical professionals have de- clared a consensus around the effcacy of treating children's gender dysphoria with puberty blockers, cross-sex hor- mones, and surgical interventions, despite mounting evi- dence to the contrary. They have dismissed grave problems undercutting the assumption that young children can consent to irreversible treatments that may deprive them of their ability to eventually produce children of their own. They have built their medical determinations on concededly weak evidence. And, they have surreptitiously compromised their medical recommendations to achieve political ends. The Court today reserves “to the people, their elected rep- resentatives, and the democratic process” the power to de- cide how best to address an area of medical uncertainty and extraordinary importance. Ante, at 525. That sovereign prerogative does not bow to “major medical organizations.” Post, at 582, n. 5 (opinion of Sotomayor, J.). “[E]xperts and elites have been wrong before—and they may prove to be wrong again.” Students for Fair Admissions, Inc., 600 U. S., at 268 (Thomas, J., concurring).

Justice Barrett, with whom Justice Thomas joins, concurring. Because the Court concludes that Tennessee's Senate Bill 1 does not classify on the basis of transgender status, it does not resolve whether transgender status constitutes a suspect

led to bans of the youth gender treatments in more than 20 states, one of which will soon be considered by the Supreme Court.” Id., at A23. 548 UNITED STATES v. SKRMETTI

class. Ante, at 517–519; see Geduldig v. Aiello, 417 U. S. 484, 496 (1974). I write separately to explain why, in my view, it does not. I As a “practical necessity,” “most legislation classifes for one purpose or another.” Romer v. Evans, 517 U. S. 620, 631 (1996). Laws distribute benefts that advantage partic- ular groups (like in-state tuition for residents), draw lines that might seem arbitrary (like income thresholds for means- tested benefts), and set rules for specifc categories of people (like a particular profession or age group). Such classifca- tions do not usually render a law unconstitutional. Instead, as a general matter, laws are presumed to be constitutionally valid, and a legislative classifcation will be upheld “so long as it bears a rational relation to some legitimate end.” Ibid. There are only a few exceptions to this rule: classifcations based on race, sex, and alienage. Racial and ethnic classif- cations receive strict scrutiny; to survive a constitutional challenge, they must be “ `narrowly tailored' ” to serve “ `compelling governmental interests.' ” Students for Fair Admissions, Inc. v. President and Fellows of Harvard Col- lege, 600 U. S. 181, 206–207 (2023); see also Regents of Univ. of Cal. v. Bakke, 438 U. S. 265, 292 (1978) (opinion of Powell, J.) (observing that the Equal Protection Clause applies “to all ethnic groups seeking protection from offcial discrimina- tion”). Classifcations based on alienage are subject to simi- larly close scrutiny.1 Nyquist v. Mauclet, 432 U. S. 1, 7 1 Alienage is a unique category. Because of Congress's broad authority over immigration, we have treated it as a suspect class only vis-à-vis the States. See, e. g., Takahashi v. Fish and Game Comm'n, 334 U. S. 410, 418–419 (1948). For the same reason, we have grounded our scrutiny of state laws as much in the Supremacy Clause as in the Equal Protection Clause. See, e. g., Toll v. Moreno, 458 U. S. 1, 9–10 (1982) (holding that a state policy precluding certain aliens from acquiring in-state status for the purpose of university tuition violated the Supremacy Clause and declining to consider equal protection arguments); Takahashi, 334 U. S., at 419 (“State laws which impose discriminatory burdens upon the entrance or Cite as: 605 U. S. 495 (2025) 549

(1977). And laws distinguishing between men and women receive intermediate scrutiny; to survive a constitutional challenge, they must be “ ` “substantially related” ' ” to achieving an “ ` “important governmental objectiv[e].” ' ” United States v. Virginia, 518 U. S. 515, 533 (1996). Beyond these categories, the set has remained virtually closed. Indeed, this Court “has not recognized any new con- stitutionally protected classes in over four decades, and in- stead has repeatedly declined to do so.” Ondo v. Cleveland, 795 F. 3d 597, 609 (CA6 2015). So in urging us to recognize transgender status as a suspect classifcation, the plaintiffs face a high bar.2 To determine whether a group constitutes a “suspect class” akin to the canonical examples of race and sex, we apply a test derived from the famous footnote 4 in United States v. Carolene Products Co. See 304 U. S. 144, 152–153, n. 4 (1938) (suggesting that “prejudice against discrete and insular minorities may be a special condition, which tends seriously to curtail the operation of those political processes ordinarily to be relied upon to protect minorities, and which may call for a correspondingly more searching judicial in- quiry”). We consider whether members of the group in question “exhibit obvious, immutable, or distinguishing char- residence of aliens lawfully within the United States confict with [the] constitutionally derived federal power to regulate immigration, and have accordingly been held invalid”). See also Graham v. Richardson, 403 U. S. 365, 376–380 (1971). 2 Because the plaintiffs contend that intermediate scrutiny rather than strict scrutiny is the correct standard, they refer to transgender status as a “quasi-suspect” class. E. g., Brief for Respondents in Support of Peti- tioner 37; see Cleburne v. Cleburne Living Center, Inc., 473 U. S. 432, 437–438 (1985) (using the phrase “quasi-suspect classifcation” to refer to classifcations that trigger “intermediate-level scrutiny”). As any form of heightened review departs from the presumption that legislative classif- cations are constitutional, I follow the Sixth Circuit in using the phrase “suspect class” or “suspect classifcation” to refer generically to all classi- fcations that trigger more than rational-basis review. See L. W. v. Skrmetti, 83 F. 4th 460, 486 (2023). 550 UNITED STATES v. SKRMETTI

acteristics that defne them as a discrete group,” whether the group has, “[a]s a historical matter, . . . been subjected to discrimination,” and whether the group is “a minority or politically powerless.” Lyng v. Castillo, 477 U. S. 635, 638 (1986). The test is strict, as evidenced by the failure of even vulnerable groups to satisfy it: We have held that the men- tally disabled, the elderly, and the poor are not suspect classes. See Cleburne v. Cleburne Living Center, Inc., 473 U. S. 432, 442 (1985) (mental disability); Massachusetts Bd. of Retirement v. Murgia, 427 U. S. 307, 313–314 (1976) (per curiam) (age); San Antonio Independent School Dist. v. Rod- riguez, 411 U. S. 1, 28 (1973) (poverty). In fact, as far as I can tell, we have never embraced a new suspect class under this test. Our restraint refects the principle that “[w]hen social or economic legislation is at issue, the Equal Protection Clause allows the States wide latitude, and the Constitution presumes that even improvident decisions will eventually be rectifed by the democratic processes.” Cleburne, 473 U. S., at 440 (citation omitted). II The Sixth Circuit held that transgender individuals do not constitute a suspect class, and it was right to do so.3 To begin, transgender status is not marked by the same sort of “ `obvious, immutable, or distinguishing characteristics' ” as race or sex. L. W. v. Skrmetti, 83 F. 4th 460, 487 (2023) (quoting Bowen v. Gilliard, 483 U. S. 587, 602 (1987)); see Lyng, 477 U. S., at 638. In particular, it is not defned by a trait that is “ `defnitively ascertainable at the moment of birth.' ” 83 F. 4th, at 487 (quoting Ondo, 795 F. 3d, at 609). The plaintiffs here, for instance, began to experience gender dysphoria at varying ages—some from a young age, others not until the onset of puberty. See Brief for Respondents 3 Justice Alito would likewise hold that transgender persons do not qualify as a suspect or quasi-suspect class. See post, at 566 (opinion con- curring in part and concurring in judgment). Though his analysis differs in emphasis, see ibid., n. 6, I understand it to be consistent with mine. Cite as: 605 U. S. 495 (2025) 551

in Support of Petitioner 8–12. Meanwhile, the plaintiffs ac- knowledge that some transgender individuals “detransition” later in life—in other words, they begin to identify again with the gender that corresponds to their biological sex. See Tr. of Oral Arg. 49, 108. Accordingly, transgender sta- tus does not turn on an “immutable . . . characteristi[c].” Lyng, 477 U. S., at 638. Nor is the transgender population a “discrete group,” as our cases require. Ibid. Instead, like classes we have de- clined to recognize as suspect, the category of transgender individuals is “large, diverse, and amorphous.” Rodriguez, 411 U. S., at 28. The World Professional Association for Transgender Health states that the term “ `transgender' can describe `a huge variety of gender identities and expres- sions.' ” 83 F. 4th, at 487 (quoting Standards of Care for the Health of Transgender and Gender Diverse People, Version 8, 23 Int'l S15 J. Transgender Health (2022)). The American Psychological Association similarly uses the phrase “ `trans- gender youth' ” as an “umbrella term” “to describe . . . varied groups” with “many diverse gender experiences.” Brief for American Psychological Association et al. as Amici Curiae 6, n. 7. Underscoring the point, plaintiffs' counsel acknowl- edged at oral argument that “there are people who fall within a transgender identity who may not ft into a binary identity.” Tr. of Oral Arg. 100. The boundaries of the group, in other words, are not defned by an easily ascertainable characteristic that is fxed and consistent across the group. Finally, holding that transgender people constitute a sus- pect class would require courts to oversee all manner of policy choices normally committed to legislative discretion. The parties agree that the States have a legitimate interest in regulating health care. They also agree that transgender status implicates physical and mental health—indeed, this case is about the medical treatment of children with gender dysphoria, which is “clinically signifcant distress resulting from the incongruence between . . . gender identity and . . . 552 UNITED STATES v. SKRMETTI

sex assigned at birth,” and which “can result in severe anxi- ety, depression, self-harm, and even suicide.” Brief for Re- spondents in Support of Petitioner 4–5. The question of how to regulate a medical condition such as gender dysphoria involves a host of policy judgments that legislatures, not courts, are best equipped to make. See Cleburne, 473 U. S., at 441–442 (declining to recognize a suspect class when the “distinguishing characteristics” of the proposed class are “relevant to interests the State has the authority to implement”). Consider just a few: What are the relevant risks and bene- fts to children of puberty blockers and hormone treatments? What is the age at which these treatments become appro- priate? 15? 16? 18? What about surgeries? Expert disagreements highlight the diffculty of such choices. As the Court recounts, England, Finland, Norway, and Sweden have raised concerns about using puberty blockers or hor- mone treatments on juveniles with gender dysphoria and have limited such treatments, in some cases by allowing them to go forward only in a research setting. See 1 App. 332–342, 409–411; 2 id., at 726–727; ante, at 505. By con- trast, the guidelines promulgated by the Endocrine Society, upon which the plaintiffs rely, broadly recommend treatment for adolescents with sustained gender dysphoria and the ca- pacity to give informed consent. App. to Pet. for Cert. 256a–259a. As we have emphasized before, “state and fed- eral legislatures [have] wide discretion to pass legislation in areas where there is medical and scientifc uncertainty.” Gonzales v. Carhart, 550 U. S. 124, 163 (2007). The prospect of courts second-guessing legislative choices in this area should set off alarm bells. Cf. Lochner v. New York, 198 U. S. 45, 72 (1905) (Harlan, J., dissenting) (“What the precise facts are it may be diffcult to say. It is enough for . . . this court to know . . . that the question is one about which there is room for debate and for an honest difference of opinion”). Cite as: 605 U. S. 495 (2025) 553

Beyond the treatment of gender dysphoria, transgender status implicates several other areas of legitimate regulatory policy—ranging from access to restrooms to eligibility for boys' and girls' sports teams. If laws that classify based on transgender status necessarily trigger heightened scrutiny, then the courts will inevitably be in the business of “closely scrutiniz[ing] legislative choices” in all these domains. Cle- burne, 473 U. S., at 441–442. To be sure, an individual law “ `inexplicable by anything but animus' ” is unconstitutional. Trump v. Hawaii, 585 U. S. 667, 706 (2018). But legislatures have many valid reasons to make policy in these areas, and so long as a statute is a rational means of pursuing a legiti- mate end, the Equal Protection Clause is satisfed.

III The conclusion that transgender individuals do not share the “obvious, immutable, or distinguishing characteristics” of “a discrete group” is enough to demonstrate that transgen- der status does not defne a suspect class. Lyng, 477 U. S., at 638. But the second factor—whether the group has, “[a]s a historical matter, . . . been subjected to discrimination,” ibid.—also poses a problem for the plaintiffs' argument. In addressing this factor, the plaintiffs assume that a his- tory of private discrimination may satisfy this condition. For instance, the plaintiffs argue that “it is undeniable that transgender individuals, as a class, have `historically been subject to discrimination including in education, employ- ment, housing, and access to healthcare.' ” Brief for United States 29; Brief for Respondents in Support of Petitioner 37 (adopting the arguments made by the United States).4 The Solicitor General confrmed at oral argument that this argu- 4 As the Court explains, the Department of Justice has reconsidered the Government's position in this case following the change in administration. Ante, at 509, n. 1. The private plaintiffs, however, have maintained the same position throughout. 554 UNITED STATES v. SKRMETTI

ment did not turn on “discrimination . . . refected in the laws.” Tr. of Oral Arg. 60. The District Court also as- sumed that a history of private discrimination could suffce to establish that a group comprises a suspect class. See L. W. v. Skrmetti, 679 F. Supp. 3d 668, 690 (MD Tenn. 2023). This assumption is mistaken. For purposes of the Four- teenth Amendment, the relevant question is whether the group has been subject to a longstanding pattern of discrimi- nation in the law. In other words, we ask whether the group has suffered a history of de jure discrimination. Existing suspect classes had such a history. Most obvi- ously, “[t]he clear and central purpose of the Fourteenth Amendment was to eliminate all offcial state sources of in- vidious racial discrimination in the States.” Loving v. Vir- ginia, 388 U. S. 1, 10 (1967). We have made that point “re- peatedly.” Students for Fair Admissions, Inc., 600 U. S., at 206 (gathering cases). In recognizing sex as a suspect class, we similarly emphasized that women faced more than a cen- tury's worth of discrimination in the law: “[N]ot until 1920 did women gain a constitutional right to the franchise. And for a half century thereafter, it remained the prevailing doc- trine that government, both federal and state, could withhold from women opportunities accorded men so long as any `basis in reason' could be conceived for the discrimination.” Vir- ginia, 518 U. S., at 531 (citation omitted); see also Frontiero v. Richardson, 411 U. S. 677, 684–685 (1973) (plurality opin- ion) (“As a result of notions such as these, our statute books gradually became laden with gross, stereotyped distinctions between the sexes”). And in protecting alienage, we under- scored the many state laws that discriminated on that ground, typically by targeting individuals of a particular national origin. See, e. g., Takahashi v. Fish and Game Comm'n, 334 U. S. 410, 427 (1948) (Murphy, J., concurring) (discussing a state law “directed in spirit and in effect solely against aliens of Japanese birth”); Yick Wo v. Hopkins, 118 U. S. 356, 373–374 (1886) (identifying ordinances that dis- Cite as: 605 U. S. 495 (2025) 555

criminated against Chinese nationals). Indeed, Congress criminalized discrimination on the basis of alienage by state actors in 1870, “in response to California legislation restrict- ing the rights of Chinese immigrants.” Rajaram v. Meta Platforms, Inc., 105 F. 4th 1179, 1183–1184 (CA9 2024); see 16 Stat. 144 (codifed, as amended, 18 U. S. C. § 242). The distinction between de jure discrimination and private animus is consistent with the Fourteenth Amendment's text and purpose. Most fundamentally, the Fourteenth Amend- ment constrains state action, not private conduct. See Na- tional Collegiate Athletic Assn. v. Tarkanian, 488 U. S. 179, 191 (1988). And state actors are entitled to a presumption that their actions turn on constitutionally legitimate motiva- tions rather than impermissible animus. Schilb v. Kuebel, 404 U. S. 357, 364 (1971). Of course, this presumption can be defeated, and a widespread history of state action that refects animus or stereotyping gives courts good reason to be suspicious of the government's motives. But because we presume that state actors abide by the Constitution, the fact of private discrimination—which is not itself unconstitu- tional, even if morally blameworthy—does not provide a basis for inferring that state actors are also likely to discrim- inate and thereby violate the Constitution. This focus on de jure discrimination is not only theoreti- cally sound—it is also judicially manageable. Courts are ill suited to conduct an open-ended inquiry into whether the volume of private discrimination exceeds some indetermi- nate threshold. By contrast, they are well equipped to ana- lyze whether there is a history of legislation that has dis- criminated against the group in question. Focusing the inquiry on de jure state action would also clarify the test for political powerlessness, which is another factor we have used to determine whether a classifcation is suspect. Carolene Products, the source of the “discrete and insular minority” test, equates political powerlessness with laws burdening those who lacked a vote. See 304 U. S., at 556 UNITED STATES v. SKRMETTI

152–153, n. 4 (citing McCulloch v. Maryland, 4 Wheat. 316, 428 (1819) (a State regulating the Federal Government); South Carolina Highway Dept. v. Barnwell Brothers, Inc., 303 U. S. 177, 184, n. 2 (1938) (a State regulating out-of-state corporations)). This kind of “political powerlessness,” which leaves the affected persons altogether unable to pro- tect themselves in the political process, tracks the experi- ence of the existing suspect classes. We have said little, however, about what “political power- lessness” means for our recognition of new suspect classes. See Lyng, 477 U. S., at 638 (stating without elaboration that close relatives are not “politically powerless”); Murgia, 427 U. S., at 313 (same for the elderly). And in the absence of clear guidance from us, lower courts have resorted to consid- ering evidence like whether the group has drawn the support of powerful interest groups, achieved equal representation in government, or obtained affrmative statutory protection from discrimination in the private sector. See, e. g., 83 F. 4th, at 487 (evaluating whether transgender litigants are supported by “major medical organizations” and “large law frms”); 679 F. Supp. 3d, at 691 (suggesting that the analysis turns on whether the group has “achiev[ed] relative[ly] equal representation in political bodies”); Grimm v. Gloucester Cty. School Bd., 972 F. 3d 586, 613 (CA4 2020) (concluding that transgender people are politically powerless because of a “dearth of openly transgender persons serving in the exec- utive and legislative branches” or in the judiciary). These markers refect sociological intuitions about a group's rela- tive political power; they do not constitute an objective, le- gally grounded standard that courts can apply consistently. A legacy of de jure discrimination, by contrast, more pre- cisely (and objectively) captures the interests that lie at the heart of the Equal Protection Clause. Because the litigants assumed that evidence of private dis- crimination could suffce for the suspect-class inquiry, they did not thoroughly discuss whether transgender individuals Cite as: 605 U. S. 495 (2025) 557

Opinion of Alito, J.

have suffered a history of de jure discrimination as a class. And because the group of transgender individuals is an insuf- fciently discrete and insular minority, the question is largely academic.5 In future cases, however, I would not recognize a new suspect class absent a demonstrated history of de jure discrimination.

* * * The Equal Protection Clause does not demand heightened judicial scrutiny of laws that classify based on transgender status. Rational-basis review applies, which means that courts must give legislatures fexibility to make policy in this area.

Justice Alito, concurring in part and concurring in the judgment. I concur in the judgment and join Parts I and II–B of the opinion of the Court. I agree with much of the discussion in Part II–A–1, which holds that Tennessee's Senate Bill 1 (SB1) does not classify on the basis of “sex,” but I set out my own analysis of this issue in Part I of this opinion. I do not join Part II–A–2 of the opinion of the Court, which con- cludes that SB1 does not classify on the basis of “transgender status.” There is a strong argument that SB1 does classify on that ground, but I fnd it unnecessary to decide that ques- tion. I would assume for the sake of argument that the law 5 The evidence that is before this Court is sparse but suggestive of rela- tively little de jure discrimination. When asked at oral argument, the Solicitor General acknowledged that “historical discrimination against transgender people may not have been refected in the laws.” Tr. of Oral Arg. 60. Counsel for the private plaintiffs, however, suggested that bans on military service for transgender individuals and on cross-dressing might qualify as de jure discrimination. See id., at 110; see also post, at 601–602 (Sotomayor, J., dissenting). Because the issue was unbriefed, I take no position on whether there is a longstanding history of de jure discrimination with respect to the relevant characteristic of transgender status. 558 UNITED STATES v. SKRMETTI

classifes based on transgender status, but I would neverthe- less sustain the law because such a classifcation does not warrant heightened scrutiny. I also do not join Part II–A– 3 of the Court's opinion because I do not believe that the reasoning employed in Bostock v. Clayton County, 590 U. S. 644 (2020), is applicable when determining whether a law classifes based on sex for Equal Protection Clause purposes.

I A To begin, I agree with the Court that SB1 does not classify on the basis of “sex” within the meaning of our equal protec- tion precedents. What those cases have always meant by “sex” is the status of having the genes of a male or female. That was the common understanding of the term in 1971 when the Court, in Reed v. Reed, 404 U. S. 71, 74, frst held that a law that discriminated against women violated the Equal Protection Clause. See, e. g., Random House Diction- ary of the English Language 1307 (1966) (defning “sex” as “the fact or character of being either male or female”); Web- ster's Third New International Dictionary 2081 (1966) (de- fning “sex” as “one of the two divisions of . . . human beings respectively designated male or female”). And all the Court's subsequent cases in this line have shared that understanding. In Frontiero v. Richardson, 411 U. S. 677 (1973), which was handed down in the next Term after Reed, a plurality referred to “sex” as “an immutable characteristic determined solely by the accident of birth.” 411 U. S., at 686. Twenty- fve years later, Justice Ginsburg's landmark opinion for the Court in United States v. Virginia, 518 U. S. 515 (1996) (VMI), exhibited the same understanding. The opinion ob- served that the “[p]hysical differences between men and women . . . are enduring” and that the “ `[i]nherent differ- ences' between men and women” are “cause for celebration.” Id., at 533. Cite as: 605 U. S. 495 (2025) 559

While the earliest cases in this line referred solely to dis- crimination on the basis of “sex,” see, e. g., Reed, 404 U. S., at 75–77; Frontiero, 411 U. S., at 682–688 (plurality opinion), later equal protection cases referred to classifcations based on “gender,” see Craig v. Boren, 429 U. S. 190, 192 (1976). But it is clear that these cases used “gender” as a synonym for “sex.” See, e. g., id., at 199 (using “sex” and “gender” interchangeably). In employing the term “gender” in this way, our opinions tracked a change in usage in ordinary speech. As the Oxford English Dictionary explains, “as sex came increasingly to mean sexual intercourse . . . , gender began to replace it . . . as the usual word for the biological grouping of males and females.” Oxford English Dictionary (3d ed., June 2011), https://doi.org/10.1093/OED/8610510183. Thus, our use of the term “gender” had no substantive sig- nifcance. None of our equal protection decisions has used “gender” in the sense in which it is now sometimes used, i. e., to denote “a group of people in a society who share particular qualities or ways of behaving which that society associates with being male, female, or another identity.” 1 For these reasons a party claiming that a law violates the Equal Protection Clause because it classifes on the basis of sex cannot prevail simply by showing that the law draws a distinction on the basis of “gender identity.” See, e. g., Merriam-Webster's Collegiate Dictionary 520 (11th ed. 2020) (defning “gender identity”). Rather, such a plaintiff must show that the challenged law differentiates between the two biological sexes: male and female.

B 1 What, then, does it mean for a law to “classify” based on sex? The succinct answer is that a law classifes based on 1 See Cambridge English Dictionary (2025), https://dictionary. cambridge.org/us/dictionary/english/gender. 560 UNITED STATES v. SKRMETTI

sex for equal protection purposes when it “[p]rescrib[es] one rule for [women], [and] another for [men].” Sessions v. Morales-Santana, 582 U. S. 47, 58 (2017). And as we have explained, the general rule is that a law meets this test if it employs an “overt gender criterion.” Craig, 429 U. S., at 198. A few examples illustrate the point. A law setting one drinking age for women and another for men is a sex classi- fcation. Id., at 191–192, 197–199. A college policy granting admission to women but not to men (or vice versa) is a sex classifcation. Mississippi Univ. for Women v. Hogan, 458 U. S. 718, 720–723 (1982); VMI, 518 U. S., at 530–531. A law imposing different citizenship requirements for children with citizen fathers compared to children with citizen mothers is a sex classifcation. Tuan Anh Nguyen v. INS, 533 U. S. 53, 59–62 (2001). What is apparent in each of these cases is that sex serves as an explicit “criterion,” dictating that a particular legal standard applies to one sex but not the other. See also Weinberger v. Wiesenfeld, 420 U. S. 636 (1975) (different rules for husbands and wives); Stanton v. Stanton, 421 U. S. 7 (1975) (different rule for men and women); Califano v. Goldfarb, 430 U. S. 199 (1977) (different rules for widows and widowers); Califano v. Webster, 430 U. S. 313 (1977) (per cu- riam) (different rule for men and women); Orr v. Orr, 440 U. S. 268 (1979) (different rule for husbands and wives); Caban v. Mohammed, 441 U. S. 380 (1979) (different rule for unwed mothers and unwed fathers); Wengler v. Druggists Mut. Ins. Co., 446 U. S. 142 (1980) (different rules for widows and widowers); Kirchberg v. Feenstra, 450 U. S. 455 (1981) (different rule for husbands and wives); Morales-Santana, 582 U. S. 47 (different rules for unwed mothers and unwed fathers). In contrast to what our cases have demanded, we have “never suggested that mere reference to sex is suffcient to Cite as: 605 U. S. 495 (2025) 561

trigger heightened scrutiny.” Ante, at 512 (citing Nguyen, 533 U. S., at 64); see also Dobbs v. Jackson Women's Health Organization, 597 U. S. 215, 236–237 (2022) (holding that ra- tional basis review applied to a prohibition on abortion, de- spite the fact that the law in question mentioned “the physi- cal health of the mother”). We have also explicitly rejected the proposition that a law classifes based on sex when it employs a non-sex classifca- tion that correlates with differential treatment of men and women. In Geduldig v. Aiello, 417 U. S. 484 (1974), for ex- ample, we considered a California insurance program that “exclude[d] from coverage certain disabilities resulting from pregnancy.” Id., at 486. Although we recognized that “only women can become pregnant,” we explained that “it does not follow that every legislative classifcation concern- ing pregnancy is a sex-based classifcation.” Id., at 496, n. 20. In the absence of a showing that the pregnancy clas- sifcation at issue was being used as a “mere pretex[t] de- signed to effect an invidious discrimination against the mem- bers of one sex or the other,” we were unwilling to conclude that it was a proxy for a sex classifcation. Id., at 496–497, n. 20. We applied a similar principle in Personnel Administrator of Mass. v. Feeney, 442 U. S. 256 (1979). There, we consid- ered a Massachusetts policy that conferred an “absolute ad- vantage” on veterans who applied for state civil service posi- tions. Id., at 264. At the time of the lawsuit, “over 98% of the veterans in Massachusetts were male,” and we acknowl- edged that “[t]he impact of the veterans' preference law upon the public employment opportunities of women has thus been severe.” Id., at 270–271. Even so, such “severe” disparate impact did not make the law a sex classifcation. The dis- tinction made by the law was “quite simply between veter- ans and nonveterans, not between men and women.” Id., at 275. And such a classifcation was not a sex classifcation 562 UNITED STATES v. SKRMETTI

unless it could be “shown that a gender-based discriminatory purpose has, at least in some measure, shaped the Massachu- setts veterans' preference legislation.” Id., at 276. The upshot of all these prior equal protection cases is that we will generally not fnd that a law classifes on the basis of sex unless it does so overtly, but that a challenger may escape this general rule by showing that a purportedly sex- neutral classifcation has been used as a “mere pretex[t] designed to effect an invidious discrimination against the members of one sex or the other.” Geduldig, 417 U. S., at 496–497, n. 20.2 2 When these principles are applied to Tennessee's SB1, it is clear that the law is not a sex classifcation. As the Court notes, SB1 classifes based on the purpose for which a minor seeks the covered medical treatments. Specifcally, it re- stricts those treatments if they are sought either for the pur- pose of “[e]nabling a minor to identify with, or live as, a pur- ported identity inconsistent with the minor's sex” or for the purpose of “[t]reating purported discomfort or distress from a discordance between the minor's sex and asserted iden- tity.” Tenn. Code Ann. §§ 68–33–103(a)(1)(A), (a)(1)(B) (2023). This scheme certainly refers to sex and may be seen

2 Contrary to the suggestion of Justice Sotomayor, this approach is fully consistent with our decision in Loving v. Virginia, 388 U. S. 1 (1967). See post, at 592, n. 10 (dissenting opinion). In Loving, the Court con- fronted a Virginia law that was plainly a “measur[e] designed to maintain White Supremacy” and that could be justifed by “no legitimate overriding purpose independent of invidious racial discrimination.” 388 U. S., at 11. The Court correctly concluded that such a law was a race classifcation, and that it “rest[ed] solely upon distinctions drawn according to race.” Ibid. It made no difference whether the law had “ `equal application' ” between the races because the Equal Protection Clause “requires the con- sideration of whether the classifcations drawn by any statute constitute an arbitrary and invidious discrimination.” Id., at 10. As I have explained, the same is true regarding sex classifcations. When a law employs any classifcation for the purpose of invidious sex discrimination, that classifcation is rightly treated as a sex classifcation. Cite as: 605 U. S. 495 (2025) 563

as indirectly related to sex, but it is clearly not the sort of discrimination between males and females that our cases have treated as sex discrimination. It does not lay down one rule for males and another for females. Instead, it clas- sifes based on something quite different: a minor's reason for seeking particular treatment. This classifcation scheme is also not a “mere pretex[t] de- signed to effect an invidious discrimination against the mem- bers of one sex or the other.” Geduldig, 417 U. S., at 496– 497, n. 20. The law begins with a panoply of legislative fndings that make clear that the legislature's purpose was to “protect the health and welfare of minors.” § 68–33–101(a). The legislature concluded that the prohibited medical proce- dures were “experimental in nature and not supported by high-quality, long-term medical studies,” and that often “a minor's discordance can be resolved by less invasive ap- proaches that are likely to result in better outcomes. ” §§ 68–33–101(b), (c). These fndings are consistent with those made by other respected bodies that cannot be charged with hostility to mi- nors experiencing gender dysphoria or to transgender people in general. See ante, at 505. And the limited scope of SB1 strongly supports the conclusion that the legislature's true purpose was exactly the one set out in the statutory fndings. SB1 targets only the experimental medical procedures that the legislature found to be unsupported and dangerous. It does not regulate any other behavior in which minors might engage for the purpose of expressing their gender identity. It says nothing at all about names, pronouns, hair styles, attire, recreational activities or hobbies, or career interests. And the law's restrictions apply only to the treatment avail- able to minors. Once individuals reach the age at which they are able to make informed decisions about medical care, the law imposes no restrictions. 3 In an effort to show that SB1 classifes based on sex, the plaintiffs, the dissent, and some of the plaintiffs' amici rely 564 UNITED STATES v. SKRMETTI

on what they understand to be the Court's reasoning in Bos- tock, 590 U. S. 644. See Brief for Respondents in Support of Petitioner 24–32; post, at 590–591 (Sotomayor, J., dissent- ing); Brief for State of California et al. as Amici Curiae 14– 16; Brief for Kentucky Plaintiffs et al. as Amici Curiae 10– 16. This argument is misguided. The decision in Bostock was based on the conclusion that the specifc language em- ployed in Title VII of the Civil Rights Act of 1964 prohibits an adverse employment action if sex is a “but-for cause” of that action. 590 U. S., at 656–660. And in feshing out what this means, the Court engaged in a controversial form of counterfactual reasoning.3 I dissented in Bostock, but I accept the decision as a precedent that is entitled to the staunch protection we give statutory interpretation deci- sions. See Kimble v. Marvel Entertainment, LLC, 576 U. S. 446, 456 (2015) (citing Patterson v. McLean Credit Union, 491 U. S. 164, 172–173 (1989)). But there is no reason to apply Bostock's methodology here. The Equal Protection Clause does not contain the same wording as Title VII, and our cases have never held that Bostock's methodology applies in cases in which a law is chal- lenged as an unconstitutional sex classifcation. On the con- trary, as I have explained, our cases have adopted an entirely different methodology. I would follow those precedents.

II My main point of disagreement with the Court concerns its analysis of the plaintiffs' argument that SB1 unconstitu- tionally discriminates on the basis of transgender status. See Brief for Respondents in Support of Petitioner 37–38. The Court holds that the law does not classify on this ground, and the Court therefore applies rational basis review. Ante, 3 Compare M. Berman & G. Krishnamurthi, Bostock was Bogus: Textual- ism, Pluralism, and Title VII, 97 Notre Dame L. Rev. 67, 98–116 (2021), with A. Koppelman, Bostock and Textualism: A Response to Berman and Krishnamurthi, 98 Notre Dame L. Rev. Refection 89, 105–110 (2022). Cite as: 605 U. S. 495 (2025) 565

at 517–519. I am uneasy with that analysis and would reject the plaintiffs' argument for a different reason: because nei- ther transgender status nor gender identity should be treated as a suspect or “quasi-suspect” class. A I will not dwell on the question whether SB1 classifes on the basis of transgender status or gender identity because, in the end, I do not think that the answer to that question has any effect on the outcome of this case. But the argu- ment that SB1 classifes on those grounds cannot easily be dismissed. As noted, the law prohibits medical procedures that are intended either to “[e]nabl[e] a minor to identify with, or live as, a purported identity inconsistent with the minor's sex,” or to “[t]rea[t] purported discomfort or distress from a discordance between the minor's sex and asserted identity.” Tenn. Code Ann. §§ 68–33–103(a)(1)(A), (a)(1)(B). Therefore, the underlying basis for the classifcation is a mi- nor's intent to express a gender identity different from the minor's biological sex. If being “transgender” is defned as “hav[ing] a gender identity that differs from . . . sex,” see Brief for Respondents in Support of Petitioner 4, then the intent to “identify with, or live as, a purported identity in- consistent with” one's sex would appear to be the natural result or consequence of being transgender. The Court nonetheless concludes that SB1 does not clas- sify based on transgender status, and in doing so, it relies chiefy on our decision in Geduldig, 417 U. S. 484. Ante, at 518. The dissent responds by denigrating Geduldig and contending that the decision should be discarded.4 Post, at 599–600 (opinion of Sotomayor, J.). I would not enter into this debate about SB1's classifca- tion scheme. I would assume for the sake of argument that 4 But see Dobbs v. Jackson Women's Health Organization, 597 U. S. 215, 236 (2022) (reaffrming Geduldig); Bray v. Alexandria Women's Health Clinic, 506 U. S. 263, 271 (1993) (same). 566 UNITED STATES v. SKRMETTI

SB1 classifes on the basis of transgender status and move on to the question whether such a classifcation is either sus- pect or “quasi-suspect” and thus warrants some form of heightened scrutiny. That important question has divided the Courts of Appeals,5 and if we do not confront it now, we will almost certainly be required to do so very soon.

B In my view, transgender status does not qualify under our precedents as a suspect or “quasi-suspect” class.6 We have never set out a hard-and-fast test that can be used to identify such classes, but, as I explain in more detail below, our deci- sions have identifed certain key factors that transgender individuals do not share with members of suspect and “quasi-suspect” classes. Transgender status is not “im- mutable,” and as a result, persons can and do move into and out of the class. Members of the class differ widely among themselves, and it is often diffcult for others to determine whether a person is a member of the class. And trans- gender individuals have not been subjected to a history of discrimination that is comparable to past discrimination against the groups we have classifed as suspect or “quasi- suspect.”

5 Compare Grimm v. Gloucester Cty. School Bd., 972 F. 3d 586, 610 (CA4 2020) (“[T]ransgender people constitute at least a quasi-suspect class”); Hecox v. Little, 104 F. 4th 1061, 1079 (CA9 2024) (“[G]ender identity is at least a `quasi-suspect class' ” (quoting Karnoski v. Trump, 926 F. 3d 1180, 1200–1201 (CA9 2019))), with L. W. v. Skrmetti, 83 F. 4th 460, 486 (CA6 2023) (“[N]either the Supreme Court nor this Court has recognized transgender status as a suspect class”); Adams v. School Bd. of St. Johns Cty., 57 F. 4th 791, 803, n. 5 (CA11 2022) (en banc) (“[W]e have grave `doubt' that transgender persons constitute a quasi-suspect class”). 6 Justice Barrett sets forth a different analysis of the question whether transgender persons qualify as a suspect or “quasi-suspect” class. See ante, p. 547 (concurring opinion). Although our approaches to that question emphasize different points, I do not see them as incompatible. Cite as: 605 U. S. 495 (2025) 567

1 In order to understand why transgender status should not be treated as either a suspect or “quasi-suspect” class, it is helpful to recall the path that led the Court to identify those groups and afford their members heightened protection. As the Court notes, ante, at 509–510, laws routinely confer bene- fts or impose burdens on particular classes of individuals, and we have long held that equal protection principles per- mit such classifcations so long as they “bea[r] some fair rela- tionship to a legitimate public purpose,” Plyler v. Doe, 457 U. S. 202, 216 (1982). We frst developed that standard during the New Deal era, when the Court was frequently called upon to decide whether economic legislation was consistent with the Consti- tution. In response to those challenges, the Court adopted the principle that “regulatory legislation affecting ordinary commercial transactions is not to be pronounced unconstitu- tional unless . . . it is of such a character as to preclude the assumption that it rests upon some rational basis within the knowledge and experience of the legislators. ” United States v. Carolene Products Co., 304 U. S. 144, 152 (1938). At the same time that the Court developed this “rational basis” standard, however, it suggested that some laws should be afforded a “narrower” presumption of constitutionality and should therefore receive “more exacting judicial scru- tiny.” Ibid., n. 4. The Court opined that a different stand- ard of review might apply to legislation “directed at particu- lar religious, or national, or racial minorities.” Id., at 153, n. 4 (citations omitted). It reasoned that a “more searching judicial inquiry” might be required for such legislation be- cause “prejudice against discrete and insular minorities may be a special condition, which tends seriously to curtail the operation of those political processes ordinarily to be relied upon to protect minorities.” Ibid. Consistent with that discussion, the Court soon held that “[c]lassifcations based solely upon race must be scrutinized 568 UNITED STATES v. SKRMETTI

with particular care, since they are contrary to our traditions and hence constitutionally suspect.” Bolling v. Sharpe, 347 U. S. 497, 499 (1954). Such classifcations, the Court later noted, “must be viewed in light of the historical fact that the central purpose of the Fourteenth Amendment was to eliminate racial discrimination emanating from offcial sources in the States.” McLaughlin v. Florida, 379 U. S. 184, 192 (1964). The discrimination that the Court had chiefy in mind was discrimination against blacks, who undoubtedly constituted a “discrete and insular minorit[y]” that was denied equal par- ticipation in the political process. Carolene Products, 304 U. S., at 153, n. 4. As our cases from the period plainly illus- trate, blacks faced widespread discrimination not only in fact but also in law. State and local authorities enforced a re- gime of offcial segregation in transportation, see Plessy v. Ferguson, 163 U. S. 537, 540 (1896), schools, see Brown v. Board of Education, 347 U. S. 483, 487–488 (1954), and all manner of public accommodations, see Watson v. Memphis, 373 U. S. 526, 528 (1963) (concerning the segregation of “mu- nicipal parks and other city owned or operated recreational facilities”). Blacks were also widely impeded from participation in the political process. For example, several States enacted “lit- eracy tests for voter registration” that were “designed to prevent African-Americans from voting.” Shelby County v. Holder, 570 U. S. 529, 536 (2013) (citing South Carolina v. Katzenbach, 383 U. S. 301, 310 (1966)). States also devised methods for excluding or impeding black citizens from serv- ing in public offce. See, e. g., Nixon v. Herndon, 273 U. S. 536, 541 (1927) (holding unconstitutional a law that excluded black citizens from “tak[ing] part in a primary election”); Anderson v. Martin, 375 U. S. 399, 400 (1964) (holding uncon- stitutional a law that required ballots to “designate the race of candidates for elective offce”). Cite as: 605 U. S. 495 (2025) 569

Given this history of pervasive discrimination and the fact that “the central purpose of the Fourteenth Amendment was to eliminate racial discrimination,” the Court concluded that racial classifcations are “constitutionally suspect, and sub- ject to the most rigid scrutiny.” McLaughlin, 379 U. S., at 192 (citation and internal quotation marks omitted). And at around the same time, the Court also treated national origin and ancestry as suspect classes, largely because of their proximal relationship to race. See, e. g., Oyama v. Califor- nia, 332 U. S. 633, 646 (1948); Korematsu v. United States, 323 U. S. 214, 216 (1944), overruled by Trump v. Hawaii, 585 U. S. 677 (2018).7 The Court has also suggested that religion is a suspect class. See Carolene Products, 304 U. S., at 152, n. 4. That determination follows from the First Amendment, which prohibits any impairment of the “free exercise” of “religion.” But because this right is expressly protected by that provi- sion, questions of religious discrimination have generally been decided on First Amendment grounds. See, e. g., Ful- ton v. Philadelphia, 593 U. S. 522, 532 (2021); Espinoza v.

7 The Court has also sometimes referred to “alienage” as a suspect class. See Nyquist v. Mauclet, 432 U. S. 1, 7 (1977). Alienage, however, is quite unlike the other suspect classes the Court has identifed. Our cases make clear that constitutional scrutiny only applies to state (not federal) laws that classify based on alienage. See Examining Bd. of Engineers, Archi- tects and Surveyors v. Flores de Otero, 426 U. S. 572, 602 (1976). And it applies to only those state laws that discriminate against aliens who are “lawfully admitted.” Ibid.; see also Plyler v. Doe, 457 U. S. 202, 219, n. 19 (1982) (“We reject the claim that `illegal aliens' are a `suspect class' ”). The Court applies such scrutiny not because state laws classifying based on alienage are inherently problematic, but rather because the Federal Government has “primary responsibility in the feld of immigration and naturalization.” Flores de Otero, 426 U. S., at 602. The identifcation of alienage as a suspect class is therefore less a result of historical discrimi- nation based on immutable characteristics and more a result of the Su- premacy Clause. See Takahashi v. Fish and Game Comm'n, 334 U. S. 410, 415–417 (1948); Truax v. Raich, 239 U. S. 33, 41–42 (1915). 570 UNITED STATES v. SKRMETTI

Montana Dept. of Revenue, 591 U. S. 464, 473–474 (2020); Masterpi ece Cakeshop, Ltd. v. Colorado Civ il Rights Comm'n, 584 U. S. 617, 638 (2018). With this history in mind, it is apparent that the circum- stances that led to the identifcation of race and national ori- gin as suspect classes were truly extraordinary. As the Court subsequently explained, the designation of a suspect class is reserved for those classes “saddled with such disabili- ties, or subjected to such a history of purposeful unequal treatment, or relegated to such a position of political power- lessness as to command extraordinary protection from the majoritarian political process.” San Antonio Independent School Dist. v. Rodriguez, 411 U. S. 1, 28 (1973). And enti- tlement to “suspect class” status is largely reserved for those groups whose members tend to “carry an obvious badge” of their membership in the suspect class, which in part explains “the severity or pervasiveness of the historic legal and politi- cal discrimination against” the group. Mathews v. Lucas, 427 U. S. 495, 506 (1976). Suspect class status is therefore generally inappropriate for “large, diverse, and amorphous” groups, Rodriguez, 411 U. S., at 28, that do not share “obvi- ous, immutable, or distinguishing characteristics that defne them as a discrete group,” Lyng v. Castillo, 477 U. S. 635, 638 (1986). See also Mathews, 427 U. S., at 506; Cleburne v. Cleburne Living Center, Inc., 473 U. S. 432, 442–443, 445 (1985). No one can doubt that race satisfes all these criteria. Ra- cial minorities experienced a long history of invidious dis- crimination and lack of political power. Race, as that con- cept was long understood in this society, is an immutable characteristic that often coincides with a visible and distin- guishable “badge” of membership in the group. Mathews, 427 U. S., at 506. And both our Constitution and our “tradi- tions” provide that discrimination based on race is pro- scribed in all but the narrowest circumstances. Bolling, 347 U. S., at 499. We have therefore viewed, and continue to Cite as: 605 U. S. 495 (2025) 571

view, racial classifcations as “inherently suspect.” Stu- dents for Fair Admissions, Inc. v. President and Fellows of Harvard College, 600 U. S. 181, 209 (2023) (internal quotation marks omitted). And since Brown v. Board of Education, 347 U. S. 483, we have struck down nearly every race- or national-origin-based classifcation that has come before us; our now-overruled affrmative action decisions were the ex- ception to the rule. Students for Fair Admissions, 600 U. S., at 211–214, 224–225 (overruling Regents of Univ. of Cal. v. Bakke, 438 U. S. 265 (1978), and Grutter v. Bollinger, 539 U. S. 306 (2003)); see also 600 U. S., at 287 (Thomas, J., concurring) (“The Court's opinion rightly makes clear that Grutter is, for all intents and purposes, overruled”).

2 This Court has never “equat[ed]” classifcations based on sex with classifcations based on race or national origin for Equal Protection Clause purposes, VMI, 518 U. S., at 532, and thus has never held that sex-based classifcations are “suspect.” But since the 1970s, the Court has recognized that such classifcations warrant more careful inspection than is provided by ordinary “rational basis” review. See ibid.; Craig, 429 U. S., at 198. We often refer to this as “height- ened scrutiny” (or “intermediate scrutiny”), and we have used the term “quasi-suspect” to describe groups that qual- ify for this form of heightened review. See, e. g., Cleburne, 473 U. S., at 442. Under heightened or intermediate scru- tiny, it must be shown that a sex-based classifcation “serves important governmental objectives and that the discrimi- natory means employed are substantially related to the achievement of those objectives.” Morales-Santana, 582 U. S., at 59 (internal quotation marks omitted). This “heightened scrutiny” standard was developed in rec- ognition of the fact that classifcations based on sex share many features with classifcations based on race. Early on, the plurality opinion in Frontiero v. Richardson observed that 572 UNITED STATES v. SKRMETTI

“our Nation has had a long and unfortunate history of sex discrimination” that resulted in “statute books . . . laden with gross, stereotyped distinctions between the sexes.” 411 U. S., at 684–685. Although the opinion acknowledged “that the position of women in America ha[d] improved markedly,” it noted that “women still face[d] pervasive, although at times more subtle, discrimination.” Id., at 685–686. That pervasive discrimination against women could be explained “in part because of the high visibility of the sex characteris- tic.” Id., at 686. And such sex-discrimination was particu- larly unfair, the opinion reasoned, because “sex, like race and national origin, is an immutable characteristic determined solely by the accident of birth.” Ibid. On these bases, the Frontiero plurality opined that classi- fcations based on sex should be treated as “inherently sus- pect,” just like classifcations based on race. Id., at 688. Although the full Court never adopted that position, it has justifed the imposition of “heightened scrutiny” on largely the same grounds. As the Court later noted in Craig, a whole range of laws still on the books refected “archaic and overbroad generalizations” and “increasingly outdated mis- conceptions concerning the role of females.” 429 U. S., at 198–199 (internal quotation marks omitted). The Court has further observed that women, like blacks and other racial minorities, tend to “carry an obvious badge” of their mem- bership in the disadvantaged class, and the Court saw this as a partial explanation for “the severity or pervasiveness” of the discrimination experienced by both groups. Math- ews, 427 U. S., at 506. And women, like blacks, had long been excluded, either by law or prejudice, from equal partici- pation in the political process. See VMI, 518 U. S., at 531. Thus, the application of “heightened scrutiny” to sex clas- sifcations can be explained in large part by the fact that sex discrimination shares many characteristics with racial discrimination: it was historically entrenched and pervasive; it was based on identifable and immutable characteristics; Cite as: 605 U. S. 495 (2025) 573

and it included barriers to full participation in the political process. Despite all this, however, the Court has not perfectly equated these two forms of discrimination. See id., at 532. We have acknowledged that the “[p]hysical differences be- tween men and women . . . are enduring” and “remain cause for celebration.” Id., at 533. For this reason, sex is not a categorically “proscribed classifcation.” Ibid. “Principles of equal protection do not require” legislators to “ignore th[e] reality” that there are real differences between men and women that may sometimes justify legislation that classifes based on sex. Nguyen, 533 U. S., at 66. And classifcations based on sex have occasionally been upheld. See, e. g., Mi- chael M. v. Superior Court, Sonoma Cty., 450 U. S. 464, 475– 476 (1981) (plurality opinion); Nguyen, 533 U. S., at 73.

Page AlthoughProof the Court Pending Publication has held that classifcations based on race, national origin, and sex call for a higher level of scru- tiny, it has frequently refused to apply such scrutiny to other classifcations. And it has done so even when those classif- cations share some characteristics with race, national origin, and sex. A few examples are suffcient to illustrate the Court's general approach. Despite the fact that poor people have often been subjected to harsh and disrespectful treat- ment, a class defned by poverty is too “large, diverse, and amorphous” to qualify as suspect or “quasi-suspect.” Rod- riguez, 411 U. S., at 28. Although age is an immutable char- acteristic, “the aged . . . have not experienced” the “ `history of purposeful unequal treatment' ” that is needed to justify a higher level of scrutiny. Massachusetts Bd. of Retirement v. Murgia, 427 U. S. 307, 313 (1976) (per curiam) (quoting Rodriguez, 411 U. S., at 28). Presence in this country in vio- lation of the immigration laws, although sometimes associ- ated with social stigma, cannot defne membership in a pro- tected class because that status is not “an absolutely 574 UNITED STATES v. SKRMETTI

immutable characteristic” and may be relevant to “proper legislative goal[s].” Plyler, 457 U. S., at 220. Family rela- tional status is likewise not entitled to elevated scrutiny be- cause “[c]lose relatives . . . have not been subjected to dis- crimination” and “do not exhibit obvious, immutable, or distinguishing characteristics that defne them as a discrete group.” Lyng, 477 U. S., at 638. Even in close cases, the Court has been notably reluctant to apply an elevated level of scrutiny. This is particularly striking in the case of persons with disabilities. In Cle- burne, the Court considered whether it should apply “[h]eightened scrutiny” to laws that classify based on intel- lectual disability. 473 U. S., at 442–443. The Court ac- knowledged that the intellectually disabled are “immutably” different and that “there have been and there will continue to be instances of discrimination against [them] that are in fact invidious.” Id., at 442, 446. Nonetheless, the Court found that “the States' interest in dealing with and providing for [these individuals] is plainly a legitimate one,” id., at 442, and that “lawmakers have been addressing their diffculties in a manner that belies a continuing antipathy or prejudice,” id., at 443. The Court further recognized that the intellec- tually disabled are a “large and diversifed group” and are not “all cut from the same pattern.” Id., at 442. In light of all these facts, the Court was reluctant to identify a new suspect or “quasi-suspect” class based on the existence of “immutable disabilities” and “some degree of prejudice from at least part of the public at large.” Id., at 445. Overall, our decisions refusing to identify new suspect and “quasi-suspect” classes exhibit two salient features. First, the identifcation of a suspect or “quasi-suspect” class has been exceedingly rare. Such status has been denied to groups, like persons with disabilities and the aged, who were found by Congress to need special legislation to protect them from widespread discrimination. See, e. g., Rehabilitation Act of 1973, 29 U. S. C. § 701 et seq.; Americans with Disabili- Cite as: 605 U. S. 495 (2025) 575

ties Act of 1990, 42 U. S. C. § 12101 et seq.; Individuals with Disabilities Education Act, 20 U. S. C. § 1400 et seq.; Age Dis- crimination in Employment Act of 1967, 29 U. S. C. § 621 et seq. Accordingly, the Court's reluctance to apply a special level of scrutiny to a proposed class should not be taken as a denial of the fact that the class has suffered from harmful discrimination or a lack of political power. Second, no single characteristic is independently suffcient to qualify a proposed class as suspect or “quasi-suspect”; in- stead, in the rare instances in which the Court has identifed a suspect or “quasi-suspect” class, it has done so based on a strong showing of multiple relevant criteria: a history of widespread and conspicuous discrimination, de facto or de jure exclusion from equal participation in the political process, and an immutable characteristic that tends to serve as an obvious badge of membership in a clearly defned and readily identifable group. 4 With this background in mind, I do not think that trans- gender status is suffciently similar to race, national origin, or sex to warrant a higher level of scrutiny. Although transgender persons have undoubtedly experi- enced discrimination, the plaintiffs and their many amici have not been able to show a history of widespread and con- spicuous discrimination that is similar to that experienced by racial minorities or women. Instead, they provide little more than conclusory statements. See, e. g., Brief for United States 29; Brief for Respondents in Support of Peti- tioner 37. But as we explained in Cleburne, heightened scrutiny cannot be justifed on the ground that a proposed class has suffered from “some degree of prejudice from at least part of the public at large.” 472 U. S., at 445. Rather, a higher level of scrutiny is reserved for those groups, like racial minorities and women, who have suffered from a long history of discrimination that is both severe and pervasive. See Frontiero, 411 U. S., at 684 (plurality opinion) (“[O]ur 576 UNITED STATES v. SKRMETTI

Nation has had a long and unfortunate history of sex discrim- ination”); Mathews, 427 U. S., at 506 (characterizing the his- toric discrimination faced by women and blacks as “sever[e] [and] pervasiv[e]”). Furthermore, there is no evidence that transgender indi- viduals, like racial minorities and women, have been ex- cluded from participation in the political process. It is cer- tainly true that the very small size of the transgender population means that the members of this group cannot wield much political clout simply by casting their votes. But that is true of “a variety of other groups . . . who cannot themselves mandate the desired legislative responses.” Cleburne, 473 U. S., at 445. And despite the small size of the transgender population, the members of this group have had notable success in convincing many lawmakers to ad- dress their problems. See Brief for Respondents 47 (citing Cal. Educ. Code Ann. § 221.5(f) (West 2021); Va. Code Ann. § 38.2–3449.1 (2020); Wash. Rev. Code Ann. § 28A.642.080 (2024)); see also Cleburne, 473 U. S., at 443 (arguing that the “distinctive legislative response” to the problems of the intel- lectually disabled “belies a continuing antipathy or prejudice and a corresponding need for more intrusive oversight by the judiciary”). The parties in this case also admit that transgender status is not an immutable characteristic. See Tr. of Oral Arg. 97– 98. Instead, a person's gender identity may “shif[t],” and a person who is transgender now may not be transgender later. Id., at 98; see also Brief for Society for Evidence-Based Gen- der Medicine as Amicus Curiae 19–25 (discussing the rates of desistance among transgender youth). Moreover, trans- gender status, unlike race and sex, is often not accompanied by visibly identifable characteristics. A person's “gender identity” is an “internal sense,” Merriam-Webster's Colle- giate Dictionary, at 520, and transgender persons as a class do not uniformly “exhibit obvious, immutable, or distinguish- ing characteristics that defne them as a discrete group,” Cite as: 605 U. S. 495 (2025) 577

Lyng, 477 U. S., at 638. Nor do they necessarily tend to “carry an obvious badge” of their membership in the class that might serve to exacerbate discrimination. Mathews, 427 U. S., at 506. Finally, the defnition of transgender status that we have been given reveals that transgender people make up a “di- verse” and “amorphous class.” Rodriguez, 411 U. S., at 28. Individuals are regarded as transgender whenever “they have a gender identity that differs from the sex they were assigned at birth.” Brief for Respondents in Support of Petitioner 4. That defnition encompasses not just biological men who permanently identify as women and biological women who permanently identify as men, but also individu- als who might identify with a particular gender at a particu- lar point in time and individuals who identify permanently or temporarily with both sexes, neither sex, or some other identity. See Brief for American Psychological Association et al. as Amici Curiae 6, and n. 7 (describing “ `transgender youth' ” as an “umbrella term” that can refer to minors who are “gender diverse” or “nonbinary”). We have previously refused to apply a higher level of scrutiny to such “amor- phous” classes for good practical reasons. See, e. g., Rodri- guez, 411 U. S., at 28; Cleburne, 473 U. S., at 442–443. Since such classes are not rigidly defned, it is hard to pin down whether they share the relevant characteristics that make closer scrutiny warranted. And it is diffcult for both courts and legislatures to identify the outer bounds of such groups. In light of all the above, I am unwilling to conclude that transgender status, like race, national origin, and sex, is enti- tled to a higher level of scrutiny than ordinary rational basis review. That conclusion, however, should not be taken as a denial of the discrimination that transgender people have faced. Nor should it be taken as an evaluation of any spe- cifc legislative action concerning transgender persons. It simply means that transgender persons, like members of other disadvantaged groups—the poor, the aged, the dis- 578 UNITED STATES v. SKRMETTI

Sotomayor, J., dissenting

abled, etc.—have not made the extraordinary showing that they are entitled to a higher level of constitutional scrutiny.

III Because transgender status is not a suspect or “quasi- suspect” class, even if Tennessee's SB1 classifes on that ground, it must be sustained so long as it “bears some fair relationship to a legitimate public purpose.” Plyler, 457 U. S., at 216. As the Court notes, SB1 easily satisfes that standard. Ante, at 522–525. I therefore agree with the Court that the judgment of the United States Court of Appeals for the Sixth Circuit should be affrmed.

Justice Sotomayor, with whom Justice Jackson joins, and with whom Justice Kagan joins as to all but Part V, dissenting.

To give meaning to our Constitution's bedrock equal pro- tection guarantee, this Court has long subjected to height- ened judicial scrutiny any law that treats people differently based on sex. See United States v. Virginia, 518 U. S. 515, 533 (1996). If a State seeks to differentiate on that basis, it must show that the sex classifcation “serves important governmental objectives and that the discriminatory means employed are substantially related to the achievement of those objectives.” Ibid. (internal quotation marks omitted). Such review (known as intermediate scrutiny) allows courts to ascertain whether the State has a sound, evidence-based reason to distinguish on the basis of sex or whether it does so in reliance on impermissible stereotypes about the sexes. Today, the Court considers a Tennessee law that categori- cally prohibits doctors from prescribing certain medications to adolescents if (and only if) they will help a patient “iden- tify with, or live as, a purported identity inconsistent with the minor's sex.” Tenn. Code Ann. § 68–33–103(a)(1)(A) (2023). In addition to discriminating against transgender Cite as: 605 U. S. 495 (2025) 579

adolescents, who by defnition “identify with” an identity “in- consistent” with their sex, that law conditions the availabil- ity of medications on a patient's sex. Male (but not female) adolescents can receive medicines that help them look like boys, and female (but not male) adolescents can receive med- icines that help them look like girls. Tennessee's law expressly classifes on the basis of sex and transgender status, so the Constitution and settled prece- dent require the Court to subject it to intermediate scrutiny. The majority contorts logic and precedent to say otherwise, inexplicably declaring it must uphold Tennessee's categorical ban on lifesaving medical treatment so long as “ `any reason- ably conceivable state of facts' ” might justify it. Ante, at 522. Thus, the majority subjects a law that plainly discrimi- nates on the basis of sex to mere rational-basis review. By retreating from meaningful judicial review exactly where it matters most, the Court abandons transgender children and their families to political whims. In sadness, I dissent. I A Begin with the medical context in which Tennessee's law operates. See Tenn. Code Ann. § 68–33–101 et seq.; see also S. B. 1, 113th Gen. Assem., 1st Extra. Sess. (2023) (SB1). Doctors in the United States prescribe hormones and pu- berty inhibitors to treat a range of medical conditions. Often, they are administered to help minors conform to the typical appearance associated with their sex identifed at birth. Children who start experiencing puberty at a prema- ture age (precocious puberty), for example, have long re- ceived puberty-delaying medications to stave off puberty until adolescence. See 1 App. 22. Adolescent boys might also receive the hormone testosterone to initiate puberty de- layed beyond its typical start. App. to Pet. for Cert. 266a. Without testosterone, puberty would “eventually initiate naturally” in most patients, but medication “is often pre- 580 UNITED STATES v. SKRMETTI

scribed to avoid some of the social stigma that comes from undergoing puberty later than one's peers.” Ibid. Adoles- cent females with delayed puberty may receive the hormone estrogen for the same reason. Ibid. After puberty begins, doctors may prescribe these same medicines to adolescents whose physical appearance does not align with what one might expect from their sex identifed at birth. An adolescent female, for example, might receive testosterone suppressors and hormonal birth control to re- duce the growth of unwanted hair on her face or body (some- times called male-pattern hair growth or hirsutism). See ibid.; see also 1 App. 100 (“[M]edications that are used to suppress testosterone can be used to address symptoms of polycystic ovarian syndrome, which can include unwanted fa- cial hair and body hair, excessive sweating, and body odor”); Brief for Experts on Gender Affrming Care as Amici Cu- riae 12 (describing the prevalence of hirsutism in people identifed as female at birth).1 An adolescent male may also receive hormones to address a benign but atypical increase in breast gland tissue (known as gynecomastia), sometimes resulting from below-average testosterone levels. See, e. g., G. Kanakis et al., EAA Clinical Practice Guidelines—Gyne- comastia Evaluation and Management, 7 Andrology 778, 779– 780 (2019). Like any medical treatment, hormones and pu- berty blockers come with the potential for side effects. See, e. g., App. to Pet. for Cert. 266a–267a; 2 App. 970–974; Brief for United States 45–46. Yet patients and their parents may decide to proceed with treatment on the advice of a physician, despite the accompanying medical risks. Physicians prescribe these same medications to transgen- der adolescents, whose gender identity is inconsistent with their sex identifed at birth. Hormones and puberty block- ers help align transgender adolescents' physical appearance with their gender identity, as they do when prescribed to 1 See also W. Hafsi & J. Kaur, Hirsutism, StatPearls (May 3, 2023), https://www.ncbi.nlm.nih.gov/ books/NBK470417/. Cite as: 605 U. S. 495 (2025) 581

adolescents who want to align their appearances with their sex identifed at birth. The same puberty suppressants pre- scribed to pause the onset of precocious puberty can pause puberty for transgender adolescents, giving them “time to further understand their gender identity.” App. to Pet. for Cert. 256a. Hormone therapy later allows transgender teens to initiate puberty consistent with their gender identity. That typi- cally involves testosterone for adolescent transgender boys (who were identifed as female at birth) and testosterone sup- pression and estrogen for adolescent transgender girls (who were identifed as male at birth). Such treatments help ado- lescents identifed as female at birth look more masculine and those identifed as male at birth look more feminine. As is true for most medical treatment for minors, puberty block- ers and hormones should be administered only after a com- prehensive and individualized risk-beneft assessment, and with parental consent. See American Medical Association, Code of Medical Ethics, 2.2.1 Pediatric Decision Making (2022); E. Coleman et al., Standards of Care for the Health of Transgender and Gender Diverse People, Version 8, 23 Int'l J. Transgender Health S1, S58 (2022).2 Transgender adolescents' access to hormones and puberty blockers (known as gender-affrming care) is not a matter of mere cosmetic preference. To the contrary, access to care can be a question of life or death. Some transgender adoles- cents suffer from gender dysphoria, a medical condition char- acterized by clinically signifcant and persistent distress resulting from incongruence between a person's gender iden- tity and sex identifed at birth. App. to Pet. for Cert. 251a– 252a. If left untreated, gender dysphoria can lead to severe anxiety, depression, eating disorders, substance abuse, self- harm, and suicidality. See, e. g., Coleman, 23 Int'l J. Trans- 2 The use of surgery to treat gender dysphoria, which Justice Thomas addresses in some detail, see ante, at 535–536 (concurring opinion), is not at issue in this case. 582 UNITED STATES v. SKRMETTI

gender Health, at S62. Suicide, in particular, is a major con- cern for parents of transgender teenagers, as the lifetime prevalence of suicide attempts among transgender individu- als may be as high as 40%. App. to Pet. for Cert. 264a. Tragically, studies suggest that as many as one-third of transgender high school students attempt suicide in any given year.3 When provided in appropriate cases, gender-affrming medical care can meaningfully improve the health and well- being of transgender adolescents, reducing anxiety, depres- sion, suicidal ideation, and (for some patients) the need for more invasive surgical treatments later in life.4 That is why the American Academy of Pediatrics, American Medical As- sociation, American Psychiatric Association, American Psy- chological Association, and American Academy of Child Ado- lescent Psychiatry all agree that hormones and puberty blockers are “appropriate and medically necessary” to treat gender dysphoria when clinically indicated. Id., at 285a.5

3 See M. Johns et al., Transgender Identity and Experiences of Violence Victimization, Substance Use, Suicide Risk, and Sexual Risk Behaviors Among High School Students, 68 Morbidity and Mortality Weekly Rep. 67, 70 (2019). 4 The majority and Justice Thomas make much of recent changes to the routine provision of gender-affrming care to minors in Norway, Swe- den, and England. Ante, at 505, 524–525; ante, at 537–539 (concurring opinion). While all three countries have committed to researching fur- ther the risks and benefts of prescribing puberty blockers and hormones to adolescents, none has categorically banned doctors from providing pa- tients with all gender-affrming care where medically necessary. See Brief for Foreign Non-Proft Organizations as Amici Curiae 4–13. 5 Far from signaling that “self-proclaimed experts” can determine “ `the meaning of the Constitution,' ” ante, at 530 (opinion of Thomas, J.), this reference to the positions of major medical organizations is simply one piece of factual context relevant to the Court's assessment of whether SB1 is substantially related to the achievement of an important government interest. See infra, at 586–587 (describing the intermediate scrutiny standard). Indeed, even Justice Thomas seems to recognize that some scientifc and medical evidence (at least that which is consistent with his view of the merits) is relevant to the questions this case presents. See ante, Cite as: 605 U. S. 495 (2025) 583

B Tennessee has taken a different tack. The State enacted SB1 to categorically prohibit physicians from prescribing pu- berty blockers and hormone therapy for the purpose of treat- ing gender dysphoria in minors. Tennessee's blanket ban applies only when hormones and puberty blockers are pre- scribed to “[e]nabl[e] a minor to identify with, or live as, a purported identity inconsistent with the minor's sex” or to alleviate “discomfort or distress from a discordance between the minor's sex and asserted identity.” Tenn. Code Ann. § 68–33–103(a)(1). SB1 leaves untouched the use of the same drugs to treat any other medical condition, including delayed (or early) puberty and any other “physical or chemi- cal abnormality present in a minor that is inconsistent with the normal development of a human being of the minor's sex.” § 68–33–102(1). In other words, SB1 allows physi- cians to help align adolescents' physical appearance with their gender identity (despite associated risks) if it is consist- ent with their sex identifed at birth, but not if inconsistent. Indeed, Tennessee's stated interests in SB1 include “encour- aging minors to appreciate their sex.” § 68–33–101(m).

C Tennessee's ban applies no matter what the minor's par- ents and doctors think, with no regard for the severity of the minor's mental-health conditions or the extent to which treatment is medically necessary for an individual child. The stories of the plaintiffs in this case refect the stakes of that harsh reality. Ryan Roe, now 16, felt as early as elementary school that he “was a boy.” App. to Pet. for Cert. 234a. Before pu- berty, Ryan thought “there wasn't that much of a difference between boys and girls” and that he “could manage existing in the middle.” Ibid. As puberty approached, however,

at 534, 535, 539, 544 (referencing the Cass Review and various peer-re- viewed medical journals). 584 UNITED STATES v. SKRMETTI

Ryan grew increasingly anxious about the impending changes to his body. He started throwing up every morning before school. As his voice changed, Ryan contemplated going mute. Id., at 235a. Eventually, after two years of psychotherapy and extensive consultations with his parents and doctors, Ryan's physicians prescribed him testosterone. Ryan began to fnd his voice again. He started raising his hand in class, participating in school, and looking at himself in the mirror. Ryan attests that “[g]ender-affrming health care saved [his] life.” Id., at 234a. For Ryan's parents, “[i]t is simply not an option to cut [him] off from this care.” Id., at 246a. “I worry about his ability to survive,” Ryan's mother attests. “[L]osing him would break me.” Ibid. L. W., too, began to question her gender as early as fourth grade. At the time, she felt like she was “drowning” and “trapped in the wrong body,” often sick at school because she “did not feel comfortable using the boy's bathroom.” Id., at 223a. At age 13, L. W. and her parents sought out medical treatment. Puberty blockers and estrogen, prescribed to L. W. after consultation with her parents and doctors, changed her life. “We have a confdent, happy daughter now, who is free to be herself,” her mom explains. 1 App. 85. “As a mother, I could not bear watching my child go through physical changes that would destroy her well-being and cause her life-long pain.” Id., at 86. Echoing a similar refrain, John Doe and his family attest that John felt from an early age he was a boy. He chose a male name for himself around the age of three. As puberty ap- proached, John grew terrifed of undergoing what he saw as “the wrong puberty,” recognizing that “some of those changes could be permanent.” App. to Pet. for Cert. 232a. After years of psychotherapy, he began taking puberty-delaying medication. His mother, who “shed many tears during the frst year” of this process, acknowledges that “John's gender transition has not been easy.” 1 App. 95. Yet she attests that John's access to medical treatment is “the one thing” that gives her hope that he can “have a fulflling life.” Id., at 94. Cite as: 605 U. S. 495 (2025) 585

D Faced with the choice between leaving Tennessee in search of treatment and risking their children's lives, Ryan, John, L. W., and their parents sued to enjoin SB1. The United States intervened in support.6 Together, they ar- gued that SB1 unconstitutionally discriminates on the basis of sex and transgender status. After review of the factual record, the District Court agreed, holding that the law would likely fail intermediate scrutiny because its targeted ban on promoting inconsistency with sex was not substantially re- lated to Tennessee's asserted interest in protecting minors from dangerous medical procedures. L. W. v. Skrmetti, 679 F. Supp. 3d 668, 710 (MD Tenn. 2023). A divided panel of the Sixth Circuit reversed. All three judges appeared to “accept the premise” that “the statut[e] treat[s] minors differently based on sex.” L. W. v. Skrmetti, 83 F. 4th 460, 481 (2023); see also id., at 484 (“[T]he necessity of heightened review . . . will not be present every time that sex factors into a government decision”). Yet the majority refused to apply intermediate scrutiny because it believed that the law did not necessarily “disadvantage `persons' based on their sex.” Id., at 483. Because the Sixth Circuit never applied intermediate scrutiny to SB1, the only ques- tion this Court must decide is whether the Constitution re- quired it to do so. II A The level of constitutional scrutiny courts apply in review- ing state action is enormously consequential. Where a state law neither “proceeds along suspect lines nor infringes fun- damental constitutional rights,” reviewing courts generally 6 Although the United States submitted a letter to this Court changing its position on the equal protection question after the completion of oral argument, see ante, at 509, n. 1 (majority opinion), the United States has neither withdrawn its briefs nor sought to dismiss this case. The United States therefore remains the petitioner in this case. 586 UNITED STATES v. SKRMETTI

uphold a challenged law under the Equal Protection Clause so long as “any reasonably conceivable state of facts . . . could provide a rational basis for the classifcation.” FCC v. Beach Communications, Inc., 508 U. S. 307, 313 (1993). That lenient standard, which the majority erroneously ap- plies today, demands hardly more than a cursory glance at the State's reasons for legislating. This Court has long recognized, however, that a more “searching” judicial review is warranted when the rights of “discrete and insular minorities” are at stake. United States v. Carolene Products Co., 304 U. S. 144, 153, n. 4 (1938). Because such minorities often face systemic barri- ers to vindicating their interests through the political proc- ess, courts have a comparative advantage over the elected branches in safeguarding their rights. Ibid. Such judicial scrutiny is at its apex in reviewing laws that classify on the basis of race and national origin. States may not enact laws that classify on those bases unless they can pass through the “daunting two-step examination known in our cases as `strict scrutiny.' ” Students for Fair Admissions, Inc. v. President and Fellows of Harvard College, 600 U. S. 181, 206 (2023); see id., at 206–207 (“Under that standard we ask . . . whether the racial classifcation is used to `further compelling govern- mental interests' ” and then “whether the government's use of race is `narrowly tailored'—meaning `necessary'—to achieve that interest”). For nearly half a century, the Court has applied a different standard, known as intermediate scrutiny, to all “statutory classifcations that distinguish between males and females.” Nevada Dept. of Human Resources v. Hibbs, 538 U. S. 721, 728 (2003); see Craig v. Boren, 429 U. S. 190, 197–199 (1976). States can differentiate on the basis of sex only to “ `serv[e] important governmental objectives' ” and only if the sex clas- sifcation is “ `substantially related to the achievement of those objectives.' ” Hibbs, 538 U. S., at 728. The standard is an intermediate one because it strikes an important bal- Cite as: 605 U. S. 495 (2025) 587

ance. On the one hand, there are some genuine “[p]hysical differences between men and women,” so not all sex-based legislation is discriminatory or constitutionally proscribed. Virginia, 518 U. S., at 533. On the other hand, sex-based legislation always presents a serious risk of invidious dis- crimination that relies on “overbroad generalizations about the different talents, capacities, or preferences of males or females.” Ibid. Intermediate scrutiny is the core judicial tool to differentiate innocuous sex-based laws from discrimi- natory ones. B SB1 plainly classifes on the basis of sex, so the Constitu- tion demands intermediate scrutiny. Recall that SB1 pro- hibits the prescription of hormone therapy and puberty blockers only if done to “[e]nabl[e] a minor to identify with, or live as, a purported identity inconsistent with the minor's sex” or to alleviate “discomfort or distress from a discord- ance between the minor's sex and asserted identity.” Tenn. Code Ann. § 68–33–103(a)(1). Use of the same drugs to treat any other disease is unaffected. § 68–33–103(b)(1) (A). Physicians may continue, for example, to prescribe hormones and puberty blockers to treat any “physical or chemical abnormality present in a minor that is inconsistent with the normal development of a human being of the minor's sex.” § 68–33–102(1). What does that mean in practice? Simply that sex deter- mines access to the covered medication. Physicians in Ten- nessee can prescribe hormones and puberty blockers to help a male child, but not a female child, look more like a boy; and to help a female child, but not a male child, look more like a girl. Put in the statute's own terms, doctors can facili- tate consistency between an adolescent's physical appearance and the “normal development” of her sex identifed at birth, but they may not use the same medications to facilitate “in- consisten[cy]” with sex. All this, the State openly admits, 588 UNITED STATES v. SKRMETTI

in service of “encouraging minors to appreciate their sex.” § 68–33–101(m). Like any other statute that turns on inconsistency with a protected characteristic, SB1 plainly classifes on the basis of sex. A simple analogy illustrates the point. Suppose Ten- nessee prohibited minors from attending “ `any services, ritu- als, or assemblies if done for the purpose of allowing the minor to identify with a purported identity inconsistent with the minor's religion.' ” Brief for Yale Philosophers as Amici Curiae 10. No one would seriously dispute that such a rule classifes on the basis of religion. Whether the law prohibits a minor from attending any particular religious service turns on the minor's religion: A Jewish child can visit a synagogue but not a church, while a Christian child can attend church but not the synagogue. SB1 operates in the same way. Consider the mother who contacts a Tennessee doctor, concerned that her adolescent child has begun growing unwanted facial hair. This hair growth, the mother reports, has spurred signifcant distress because it makes her child look unduly masculine. The doc- tor's next step depends on the adolescent's sex. If the pa- tient was identifed as female at birth, SB1 allows the physi- cian to alleviate her distress with testosterone suppressants. See App. to Pet. for Cert. 266a (describing such treatments); 1 App. 100 (same). What if the adolescent was identifed male at birth, however? SB1 precludes the patient from re- ceiving the same medicine. Now consider the parents who tell a Tennessee pediatri- cian that their teenage child has been experiencing an un- wanted (but medically benign) buildup of breast gland tissue. See supra, at 580. Again, the pediatrician's next move de- pends on the patient's sex. Identifed male at birth? SB1 allows the physician to prescribe hormones to reduce the buildup of such tissue. Yet a child identifed as female at birth experiencing the same (or more) distress must be de- nied the same prescription. In both scenarios, SB1 “pro- Cite as: 605 U. S. 495 (2025) 589

vides that different treatment be accorded to [persons] on the basis of their sex,” and therefore necessarily “establishes a classifcation subject to scrutiny under the Equal Protec- tion Clause.” Reed v. Reed, 404 U. S. 71, 75 (1971).7 The Sixth Circuit apparently agreed. 83 F. 4th, at 481 (accepting the premise that “the statut[e] treat[s] minors differently based on sex”). Tennessee, too, essentially concedes the point. It admits that a prohibition on wearing clothing “ `inconsistent with' ” the wearer's sex would trigger intermediate scrutiny, as would a law prohibiting professionals from working in jobs “ `inconsistent with' ” their sex. Brief for Respondents 25. That is because for some jobs and some outfts, “a male can have the job” or wear the outft, “and a female cannot.” Ibid. SB1 draws exactly the same kind of sex-based line: For some treatments that help adolescents look and feel more masculine, a male minor can have the treatment, and a fe- male minor cannot.8

7 Justice Alito insists that the words “sex” and “gender” in our equal protection precedents refer to an “ `immutable characteristic determined solely by the accident of birth.' ” Ante, at 558 (opinion concurring in part and concurring in judgment) (quoting Frontiero v. Richardson, 411 U. S. 677, 686 (1973)). SB1 discriminates along those very lines: Adolescents displaying male “characteristic[s]” at birth are precluded from accessing the same medications those with female characteristics can freely receive. Id., at 686. 8 The majority dismisses out of hand the United States' assertion that SB1 is designed to “ `force boys and girls to look and live like boys and girls,' ” Brief for United States 23, urging that any suggestion of sex stere- otyping is relevant only to whether a law that classifes on the basis of sex fails intermediate scrutiny. Ante, at 516. That argument ignores that a law policing a sex stereotype, like the hypothetical requirement that all children wear “sex-consistent clothing,” can itself qualify as sex-based government action that triggers intermediate scrutiny. See United States v. Virginia, 518 U. S. 515, 531 (1996); Bostock v. Clayton County, 590 U. S. 644, 660 (2020). The clothing law would tolerate from a female minor at least some behavior (wearing a skirt, for example) that it pro- scribes for male minors and thereby treat minors differently on the basis 590 UNITED STATES v. SKRMETTI

That SB1 conditions a patient's access to treatment even in part on her sex is enough to trigger intermediate scrutiny. This Court's equal protection precedents ask only whether a law “differentiates on the basis of gender.” Sessions v. Morales-Santana, 582 U. S. 47, 58 (2017). If so, the law “at- tract[s] heightened review under the Constitution's equal protection guarantee.” Ibid. A long line of this Court's equal protection precedents confrms that much. See Hibbs, 538 U. S., at 728 (“[S]tatutory classifcations that distinguish between males and females are subject to heightened scru- tiny”); Virginia, 518 U. S., at 531 (“Parties who seek to defend gender-based government action must demonstrate an `exceedingly persuasive justifcation' for that action”); J. E. B. v. Alabama ex rel. T. B., 511 U. S. 127, 136 (1994) (“[A]ll gender-based classifcations today” “warran[t] . . . heightened scrutiny”). That is why an Alabama statute that “authoriz[es] the imposition of alimony obligations on hus- bands, but not on wives,” “ `establishes a classifcation sub- ject to scrutiny under the Equal Protection Clause' ”: The plaintiff, “Mr. Orr[,] bears a burden he would not bear were he female.” Orr v. Orr, 440 U. S. 268, 273, 278 (1979). This Court's decision in Bostock v. Clayton County, 590 U. S. 644 (2020), confrms the classifcation on SB1's face. As Bostock explained in the context of Title VII's prohibition on employment discrimination, “it is impossible to discriminate against a person for being homosexual or transgender with- out discriminating against that individual based on sex.” Id., at 660. In deciding that discrimination based on incon- gruence between sex and gender identity was discrimination “because of sex,” Bostock asked the very same question our equal protection precedents do: whether “changing the em- ployee's sex would have yielded a different choice by the em- ployer.” Id., at 659–660; cf. Students for Fair Admissions, Inc., 600 U. S., at 231 (applying strict scrutiny to government of sex. In any event, the United States need not rest on a theory of sex stereotyping here because SB1 classifes by sex on its face. Cite as: 605 U. S. 495 (2025) 591

actions that treat people differently “on the basis of race”).9 The answer was clearly yes, for the simple reason that dis- crimination against transgender employees necessarily “pe- nalizes a person identifed as male at birth for traits or ac- tions that it tolerates in an employee identifed as female at birth.” Bostock, 590 U. S., at 660. Nor was it a defense to liability that the discrimination might apply equally to both sexes: “[A]n employer who fres a woman, Hannah, because she is insuffciently feminine and also fres a man, Bob, for being insuffciently masculine” in both cases “fres an individ- ual in part because of sex.” Id., at 659. The same is true of SB1. By depriving adolescents of hormones and puberty blockers only when such treatment is “inconsistent with” a minor's sex, the law necessarily deprives minors identifed as male at birth of the same treatment it tolerates for an adolescent identifed as female at birth (and vice versa). 9 Justice Thomas and Justice Alito observe, correctly, that the Equal Page Proof Protection Clause and Title Pending Publication VII use different words. Ante, at 564 (opin- ion of Alito, J.); ante, at 527 (opinion of Thomas, J.). Yet that difference in wording does not change that this Court's equal protection precedents have always required courts to ask the same question this Court consid- ered in Bostock: that is, whether a law “differentiates on the basis of gen- der.” Sessions v. Morales-Santana, 582 U. S. 47, 58 (2017). To be sure, the constitutional analysis diverges from Title VII once a court identifes a law or policy that differentiates on the basis of sex. That is because the Constitution tolerates governmental differentiation on that basis if it survives intermediate scrutiny. Virginia, 518 U. S., at 533. Title VII offers employers no similar opportunity to justify sex discrimina- tion, so the inquiry largely concludes once an employee establishes that she was treated worse because of sex or another protected trait. See Muldrow v. St. Louis, 601 U. S. 346, 354 (2024). There is no reason to think, however, that a facial classifcation like SB1 could simultaneously be sex based under Title VII and sex neutral under the Equal Protection Clause. See General Elec. Co. v. Gilbert, 429 U. S. 125, 133 (1976) (“Par- ticularly in the case of defning the term `discrimination,' which Congress has nowhere in Title VII defned, [equal protection] cases afford an exist- ing body of law analyzing and discussing that term in a legal context not wholly dissimilar to the concerns which Congress manifested in enacting Title VII”). 592 UNITED STATES v. SKRMETTI

III Notwithstanding that SB1 distinguishes between males and females in the medical treatments it authorizes, the Sixth Circuit declined to apply intermediate scrutiny. It be- lieved SB1's treatment of both sexes to be “evenhande[d],” 83 F. 4th, at 479, meaning (in the panel's judgment) the clas- sifcations were not “invidious” or “unfai[r].” Id., at 483– 484. Intermediate scrutiny, of course, is how this Court de- termines whether a particular sex-based classifcation is in- vidious or unfair. See, e. g., Virginia, 518 U. S., at 531. The Sixth Circuit thus effectively held that intermediate scrutiny did not apply to SB1 because it thought SB1 might well pass such scrutiny. Even the majority today does not endorse this circular approach.10 Though it skirts the Sixth Circuit's error, the majority rests its conclusion on an equally implausible ground: that SB1's prohibition on treatments “inconsistent with [a] mi- nor's sex” contains no sex classifcation at all. Tenn. Code Ann. § 68–33–103(a)(1). As the statute's text itself makes clear, that conclusion is indefensible.

10 Justice Alito, for his part, suggests that a law does not “classify” on the basis of sex unless it explicitly creates one rule for the class of all women and another for the class of all men. Ante, at 559–562. The Four- teenth Amendment, however, “protect[s] persons, not groups.” Adarand Constructors, Inc. v. Peña, 515 U. S. 200, 227 (1995). “ `[A]t the heart of the Constitution's guarantee of equal protection,' ” this Court has said, “ `lies the simple command that the Government must treat citizens as individuals, not as simply components of a racial, religious, sexual or na- tional class.' ” Students for Fair Admissions, Inc. v. President and Fel- lows of Harvard College, 600 U. S. 181, 223 (2023) (quoting Miller v. John- son, 515 U. S. 900, 911 (1995)). That SB1 imposes sex-based classifcations on Tennessee boys as well as girls does not resolve the equal protection problem: If anything, it exacerbates it. See Loving v. Virginia, 388 U. S. 1, 8 (1967) (“[W]e reject the notion that the mere `equal application' of a statute containing racial classifcations is enough to remove the classifca- tions from the Fourteenth Amendment's proscription of all invidious ra- cial discriminatio[n] . . . ”). Cite as: 605 U. S. 495 (2025) 593

A How does the majority wriggle itself (and the Sixth Cir- cuit) free of any obligation to take a closer look? It ab- stracts away the sex classifcation on SB1's face, asserting that the law classifes based only on “age” and “medical pur- pose.” The theory, apparently, is that SB1 is sex neutral because it simply allows doctors to “administer puberty blockers or hormones to minors to treat certain conditions but not to treat gender dysphoria.” Ante, at 511. Unlike a law that prohibits attendance at a religious service “incon- sistent with” the attendee's religion, the majority says, “[a] law prohibiting the administration of specifc drugs for par- ticular medical uses” simply does not trigger heightened scrutiny. Ante, at 516. The problem with the majority's argument is that the very “medical purpose” SB1 prohibits is defned by reference to the patient's sex. Key to whether a minor may receive pu- berty blockers or hormones is whether the treatment facili- tates the “medical purpose” of helping the minor live or appear “inconsistent with” the minor's sex. That is why changing a patient's sex yields different outcomes under SB1. Again, take the adolescent distressed by newly devel- oping facial hair. Was the patient identifed female at birth? SB1 authorizes the prescription of medication. Male at birth? SB1 prohibits it. For truly sex-neutral laws, it is impossible to imagine a single scenario where changing a patient's sex yields a differ- ent result. To borrow from the majority's catalog of appar- ently benign medical-use distinctions, imagine Tennessee al- lowed consumption of DayQuil to ease coughs, but not minor aches and pains. See ante, at 513. The regulated medical purposes (treatment of coughs, aches, and pains) are unre- lated to sex, so a patient's sex will never determine whether she can consume DayQuil. All that matters is whether the patient has a cough. 594 UNITED STATES v. SKRMETTI

So too for New York's ban on assisted suicide, which the majority equates to SB1. Ante, at 511. In Vacco v. Quill, 521 U. S. 793 (1997), this Court subjected the assisted-suicide ban to rational-basis review because it neither “treat[ed] anyone differently from anyone else” nor “dr[ew] any distinc- tions between persons.” Id., at 800. In New York, the Court explained, “[e]veryone” can “refuse unwanted lifesav- ing medical treatment” and “no one is permitted to assist a suicide.” Ibid. Yet unlike for SB1, neither sex nor any other protected characteristic distinguished the terminally ill patient who could permissibly “ `hasten death' ” from an- other prohibited from doing so. Id., at 800–801. All that mattered was the patient's existing connection to life- support systems: Those connected could lawfully hasten death by discontinuing treatment, while others (who re- quired a prescription for lethal medication to do so) could not. The patient's sex (or race, or national origin) would never decide the outcome. SB1, by contrast, renders every treatment decision it regulates dependent on two things: a minor's sex identifed at birth, and the consistency of the requested treatment with that sex. That the majority fnds a way to recast SB1 in sex-neutral terms is no evidence that SB1 is sex neutral in the way hypo- thetical prohibitions on DayQuil or assisted suicide would be. Contra, ante, at 513–514. The majority emphasizes that, in Tennessee, “no minor may be administered puberty blockers or hormones to treat gender dysphoria,” while “minors of any sex may be administered puberty blockers or hormones for other purposes.” Ante, at 515. But nearly every discrimi- natory law is susceptible to a similarly race- or sex-neutral characterization. A prohibition on interracial marriage, for example, allows no person to marry someone outside of her race, while allowing persons of any race to marry within their races. See Loving v. Virginia, 388 U. S. 1, 9 (1967).11 11 Justice Alito takes the position that this Court scrutinized and in- validated Virginia's antimiscegenation law because of its impermissible purpose “ `to maintain White Supremacy' ” and not simply because it clas- Cite as: 605 U. S. 495 (2025) 595

The same is true of a hypothetical law prohibiting attendance at services “inconsistent with” a child's religion, while allow- ing all children to attend religion-consistent services. See supra, at 588. Indeed, the majority itself seems to recog- nize that laws prohibiting professions “inconsistent” with a person's sex, marriages “inconsistent” with a person's race, or religious services “inconsistent” with a person's faith must be subject to heightened review, even if rewritten as ostensi- bly neutral prohibitions on sex-, race-, and faith-inconsistent behavior. See ante, at 514–515. And although the major- ity insists that its logic would not apply to the hypothetical religion-consistent services law, ante, at 515, it offers no principled reason to differentiate that law from SB1's prohi- bition on promoting “inconsisten[cy] with” the patient's sex. B Recognizing, perhaps, that this Court already decided in Bostock that discrimination based on incongruence between sex and gender identity was itself discrimination “because of sex,” the majority seeks to distinguish Bostock away. Un- like in Bostock, the majority urges, “changing a minor's sex or transgender status does not alter the application of SB1.” Ante, at 520. Again, it emphasizes that no “medical treat- ment” under SB1 is actually doled out on the basis of sex, because (it says) medical “treatment” necessarily encom- passes “both a given drug and the specifc indication for which it is being administered.” Ante, at 513, 519–520. The majority's logic is as follows: “If a transgender boy [who was identifed as female at birth] seeks testosterone to treat sifed on the basis of race. Ante, at 562, n. 2. Of course, that is not what Loving said. See 388 U. S., at 11 (“[T]he Equal Protection Clause de- mands that racial classifcations . . . be subjected to the `most rigid scru- tiny' ”); see also ante, at 514 (majority opinion). In any event, the notion that some category of laws employing sex classifcations should be scruti- nized only if the purpose is “invidious sex discrimination,” ante, at 562, n. 2 (opinion of Alito, J.), fips the equal protection inquiry on its head. The whole purpose, after all, of intermediate scrutiny is to separate invidi- ous sex classifcations from permissible ones. 596 UNITED STATES v. SKRMETTI

his gender dysphoria, SB1 prevents a healthcare provider from administering it to him.” Ante, at 520. “If you change his biological sex from female to male,” the majority says, “SB1 would still not permit him the hormones he seeks because he would lack a qualifying diagnosis for the testos- terone—such as a congenital defect, precocious puberty, dis- ease, or physical injury.” Ibid. As should be abundantly clear by this point, the majority's recharacterization of SB1 is impossible to reconcile with the statute's plain terms. SB1 allows physicians to prescribe hormones and puberty blockers to treat not just some de- fned category of cancers and rashes, but any “physical or chemical abnormality present in a minor that is inconsistent with the normal development of a human being of the minor's sex.” § 68–33–102(1). If a minor has some physical “abnor- mality” (say, medically benign facial hair) typically perceived as “inconsistent” with her sex identifed at birth (female), SB1 deems it a “congenital defect” that physicians can treat. Change the patient's sex from female to male, and the law now forbids providing the same drugs to rid the minor of the same facial hair. In other words, SB1 makes explicit that the very reason why a doctor can treat an adolescent female for “hirsutism (male-pattern hair growth),” but not gender dysphoria is that the former will promote consistency with sex, while the latter does the opposite. Cf. ante, at 521 (ma- jority opinion). As was true in Bostock, then, the law de- prives minors of medical treatment based, in part, on sex. To be sure, when the hypothetical minor is male, not fe- male, the patient's diagnosis may well change too: The female adolescent distressed by facial hair might receive a diagnosis of hirsutism while the male adolescent may be diagnosed with gender dysphoria. See supra, at 580, 588; see also ante, at 521 (majority opinion). The same, however, was true in Bostock. When an employer fres an employee because she is transgender, the Court explained, “two causal factors may be in play”: the individual's sex and the sex “with which the Cite as: 605 U. S. 495 (2025) 597

individual identifes.” 590 U. S., at 661. Yet so long as the plaintiff 's sex is “one but-for cause of that decision,” the em- ployer discriminates on the basis of sex. Id., at 656. So too with SB1. Sex and diagnosis may both “be in play.” Id., at 661. As long as sex is one of the law's distinguishing features, however, the law classifes on the basis of sex, and the Equal Protection Clause requires application of interme- diate scrutiny. C In a fnal bid to avoid applying our equal protection prece- dents, the majority asserts that “mere reference to sex” is insuffcient to trigger intermediate scrutiny, especially in the “medical context.” Ante, at 512. Of course, not every leg- islative mention of sex triggers intermediate scrutiny. A law mandating that no person, “regardless of sex,” can con- sume a dangerous drug, for example, would be subject to rational-basis review. Yet SB1 does not just mention sex. It defnes an entire category of prohibited conduct based on inconsistency with sex. And it is hard to imagine a law that prohibits conduct “inconsistent with” sex that could avoid intermediate scrutiny. Nor does the fact that SB1 concerns the “medical context” change the relevant analysis. Ibid. No one disputes that “[s]ome medical treatments and procedures are uniquely bound up in sex” or that there are “ `biological differences between men and women.' ” Ibid. That there are such physical differences is, after all, one of the reasons why sex is not altogether a proscribed classifcation. See Virginia, 518 U. S., at 533. A law that allowed only women to receive certain breast cancer treatments, for example, might well be consistent with the Constitution's equal protection mandate if the State establishes that the relevant treatments are suited to women's (and not men's) bodies. Cf. ante, at 512 (noting “ `many' breast cancer treatments [are] approved for women only”). Laws that differentiate based on biological distinctions between men and women are precisely the sort 598 UNITED STATES v. SKRMETTI

that States might successfully defend under intermediate scrutiny. Biological differences between the sexes, how- ever, are no reason to skirt such scrutiny altogether. Fashioning a medical-context-only exception also runs counter to decades of equal protection precedents. This Court has clarifed that, although not every sex-based dis- tinction is “marked by misconception and prejudice,” Tuan Anh Nguyen v. INS, 533 U. S. 53, 73 (2001), every sex-based distinction does warrant intermediate scrutiny. See J. E. B., 511 U. S., at 136 (“[A]ll gender-based classifcations today” “warran[t] . . . heightened scrutiny” (emphasis added)). Take, for example, Tuan Anh Nguyen, where this Court assessed the constitutionality of a law imposing one set of citizenship-acquisition requirements on children born abroad out of wedlock to U. S. citizen mothers and another on those born of U. S. citizen fathers. 533 U. S., at 60. The Court ultimately decided that the “different set of rules” for fathers and mothers was “neither surprising nor troublesome from a constitutional perspective” because “[f]athers and mothers are not similarly situated with regard to the proof of biologi- cal parenthood.” Id., at 63. We reached that conclusion, however, only after demanding of the Government an ex- planation for why that sex classifcation “ `serve[d] “impor- tant governmental objectives” ' ” and how “ ` “the discrimina- tory means employed” [were] “substantially related to the achievement of those objectives.” ' ” Id., at 60 (quoting Vir- ginia, 518 U. S., at 533). In no sense did the biological dif- ferences between the sexes relieve courts of the obligation to examine the sex classifcation with a careful constitutional eye. Nor is any medical-context exception necessary be- cause intermediate scrutiny itself allows the State to main- tain classifcations where justifed by biology.

IV Having blithely dispensed with the notion that SB1 classi- fes on the basis of sex, the majority next asserts that “SB1 does not classify on the basis of transgender status.” Ante, Cite as: 605 U. S. 495 (2025) 599

at 517. That too is contrary to the statute's text and plainly wrong. SB1 prohibits Tennessee physicians from offering hor- mones and puberty blockers to allow a minor to “identify with” a gender identity inconsistent with her sex. Tenn. Code Ann. § 68–33–103(a)(1)(A). Desiring to “identify with” a gender identity inconsistent with sex is, of course, exactly what it means to be transgender. The two are wholly coex- tensive. See Oxford English Dictionary (3d ed., Dec. 2023), https://www.oed.com/dictionary/transgender_adj (Trans- gender, when used as an adjective, means “a person whose sense of personal identity and gender does not correspond to that person's sex at birth . . . ”). That is why it would defy common sense to suggest an employer's policy of fring all persons identifying with or living as an identity inconsistent with their sex does not discriminate on the basis of transgen- der status. Left with nowhere else to turn, the Court hinges its con- clusion to the contrary on the by-now infamous footnote 20 of Geduldig v. Aiello, 417 U. S. 484 (1974), which declared that discrimination on the basis of pregnancy is not discrimi- nation on the basis of sex. See id., at 496–497, n. 20. The footnote reasoned that, although “only women can become pregnant,” “[n]ormal pregnancy is an objectively identifable physical condition with unique characteristics” and “lawmak- ers are constitutionally free to include or exclude pregnancy from the coverage of legislation . . . on any reasonable basis, just as with respect to any other physical condition.” Ibid. The takeaway, according to the majority, is that “not . . . every legislative classifcation concerning pregnancy is a sex- based classifcation,” and so (apparently) not every legisla- tive classifcation concerning “gender incongruence” (at least in the context of medical treatments) classifes on the basis of transgender status. Id., at 496, n. 20. Geduldig was “egregiously wrong” when it was decided, both “[b]ecause pregnancy discrimination is inevitably sex discrimination” and because discrimination against women is 600 UNITED STATES v. SKRMETTI

so “tightly interwoven with society's beliefs about pregnancy and motherhood.” Coleman v. Court of Appeals of Md., 566 U. S. 30, 56–57 (2012) (Ginsburg, J., dissenting). That the majority must resuscitate so unpersuasive a source, widely rejected as indefensible even 40 years ago, is itself a telling sign of the weakness of its position. See S. Law, Rethinking Sex and the Constitution, 132 U. Pa. L. Rev. 955, 983 (1984) (“Criticizing Geduldig has . . . become a cottage industry”). That the Court today extends Geduldig's logic for the frst time beyond pregnancy and abortion is more troubling still. Divorced from its fact-specifc context, Geduldig's reasoning may well suggest that a law depriving all individuals who “have ever, or may someday, menstruate” of access to health insurance would be sex neutral merely because not all women menstruate. In any event, even Geduldig's faulty reasoning cannot save the majority's conclusion that SB1 is innocent of transgender discrimination. Unlike pregnancy, a desire to “identify with, or live as, a purported identity inconsistent with [one's] sex,” Tenn. Code Ann. § 68–33–103(a)(1)(A), is not some “ob- jectively identifable physical condition” that legislatures can target without reference to sex or transgender status, Ged- uldig, 417 U. S., at 496, n. 20. And while not all women are pregnant, ibid., all transgender people, by defnition, “iden- tify with, or live as, a purported identity inconsistent with [their] sex,” Tenn. Code Ann. § 68–33–103(a)(1)(A). So, un- like the classes of pregnant persons and women, the class of minors potentially affected by SB1 and transgender minors are one and the same. That SB1 discriminates on the basis of transgender status is yet another reason it must be subject to heightened scru- tiny. For one, this Court already decided in Bostock that “it is impossible to discriminate against a person for being . . . transgender without discriminating against that individual based on sex,” 590 U. S., at 660, and sex discrimination is of course subject to heightened scrutiny. Nor should there be Cite as: 605 U. S. 495 (2025) 601

serious dispute that transgender persons bear the hallmarks of a quasi-suspect class.12 See Cleburne v. Cleburne Living Center, Inc., 473 U. S. 432, 441 (1985) (describing the standard). Transgender people have long been subject to discrimina- tion in healthcare, employment, and housing, and to rampant harassment and physical violence. See Grimm v. Glouces- ter Cty. School Bd., 972 F. 3d 586, 611 (CA4 2020) (detailing that history); see also K. Barry, B. Farrell, J. Levi, & N. Vanguri, A Bare Desire To Harm: Transgender People and the Equal Protection Clause, 57 B. C. L. Rev. 507, 556–557 (2016) (describing Congress's exclusion of transgender people from the Fair Housing Act, Americans with Disabilities Act, and Rehabilitation Act). Individuals whose gender identity diverges from their sex identifed at birth (whether labeled as “transgender” at the time or not), moreover, have been subject to a lengthy history of de jure discrimination in the form of cross-dressing bans, police brutality, and anti- sodomy laws. See, e. g., K. Redburn, Before Equal Protec- tion: The Fall of Cross-Dressing Bans and the Transgender Legal Movement, 1963–86, 40 L. and Hist. Rev. 679, 685, 687 (2022); A. Lvovsky, Vice Patrol 29, 108 (2021); W. Eskridge, GayLaw: Challenging the Apartheid of the Closet 328–337 (1999) (cataloging state consensual sodomy laws, 1610–1988). Beginning in 1843, cities ranging from “major metropolitan centers such as Chicago and Los Angeles to small cities and towns including Cheyenne, Wyoming and Vermillion, South 12 Myriad courts across the country have reached the same conclusion. See, e. g., Grimm v. Gloucester Cty. School Bd., 972 F. 3d 586, 610–613 (CA4 2020); Karnoski v. Trump, 926 F. 3d 1180, 1200–1201 (CA9 2019) (per curiam); Evancho v. Pine-Richland School Dist., 237 F. Supp. 3d 267, 288–289 (WD Pa. 2017); Adkins v. New York, 143 F. Supp. 3d 134, 139 (SDNY 2015); Flack v. Wisconsin Dept. of Health Servs., 328 F. Supp. 3d 931, 951–953 (WD Wis. 2018); F. V. v. Barron, 286 F. Supp. 3d 1131, 1145 (Idaho 2018); M. A. B. v. Board of Ed. of Talbot Cty., 286 F. Supp. 3d 704, 719–722 (Md. 2018); Norsworthy v. Beard, 87 F. Supp. 3d 1104, 1119 (ND Cal. 2015). 602 UNITED STATES v. SKRMETTI

Dakota” enacted ordinances that (most commonly) criminal- ized any person “ `appear[ing] upon any public street or other public place . . . in a dress not belonging to his or her sex.' ” Redburn, 40 L. and Hist. Rev., at 687. In any event, those searching for more evidence of de jure discrimination against transgender individuals, see ante, at 554–557 (Barrett, J., concurring), need look no further than the present. The Federal Government, for example, has started expelling transgender servicemembers from the military and threaten- ing to withdraw funding from schools and nonprofts that es- pouse support for transgender individuals.13 Transgender persons, moreover, have a defning character- istic (incongruence between sex and gender identity) that plainly “ `bears no relation to [the individual's] ability to per- form or contribute to society.' ” Cleburne, 473 U. S., at 441. As a group, the class is no more “ `large, diverse, and amor- phous,' ” ante, at 551 (opinion of Barrett, J.); ante, at 570 (Alito, J., concurring in part and concurring in judgment), than most races or ethnic groups, many of which similarly include individuals with “ ` “a huge variety” ' ” of identities and experiences, ante, at 551 (opinion of Barrett, J.). (Not all racial, ethnic, or religious minorities, for example, “ `carry an obvious badge' of their membership in the disadvantaged class.” Cf. ante, at 572 (opinion of Alito, J.).) 14 As evi- denced by the recent rise in discriminatory state and federal policies and the fact that transgender people “are underrep- resented in every branch of government,” Grimm, 972 F. 3d, at 611–613, moreover, the class lacks the political power to 13 See United States v. Shilling, 605 U. S. 907 (2025); see also Defending Women From Gender Ideology Extremism and Restoring Biological Truth to the Federal Government, Exec. Order No. 14168, 90 Fed. Reg. 8615 (2025). 14 See, e. g., L. Noe-Bustamante, A. Gonzalez-Barrera, K. Edwards, L. Mora, & M. Hugo Lopez, Measuring the Racial Identity of Latinos, Pew Research Center (Nov. 2021), https://www.pewresearch.org/race-and- ethnicity/2021/11/04/measuring-the-racial-identity-of-latinos/ (highlighting the range of self-reported skin color among people who identify as Latino). Cite as: 605 U. S. 495 (2025) 603

vindicate its interests before the very legislatures and execu- tive agents actively singling them out for discriminatory treatment. See Lyng v. Castillo, 477 U. S. 635, 638 (1986). In refusing to say as much, the Court today renders trans- gender Americans doubly vulnerable to state-sanctioned discrimination.15 V SB1's classifcations by sex and transgender status clearly require the application of intermediate scrutiny. The major- ity's choice instead to subject SB1 to rational-basis review, the most cursory form of constitutional review, is not only indefensible as a matter of precedent but also extraordinarily consequential. Instead of scrutinizing the legislature's clas- sifcations with an eye towards ferreting out unconstitutional discrimination, the majority declares it will uphold Tennes- see's ban as long as there is “ `any reasonably conceivable state of facts that could provide a rational basis for the clas- sifcation.' ” Ante, at 522 (quoting Beach Communications, Inc., 508 U. S., at 313; emphasis added). That marks the frst time in 50 years that this Court has applied such defer- ential review, normally employed to assess run-of-the-mill economic regulations, to legislation that explicitly differenti- ates on the basis of sex. As a result, the Court never even asks whether Tennessee's sex-based classifcation imposes the sort of invidious discrimination that the Equal Protection Clause prohibits. The majority says that it does not want to “second-guess the lines that SB1 draws,” ante, at 524, or to “resolve” dis- agreements about the safety and effcacy of “medical treat-

15 Of course, regardless of whether transgender persons constitute a suspect class, courts must strike down any law that refects the kind of “irrational prejudice” that this Court has recognized as an illegitimate basis for government action. Cleburne v. Cleburne Living Center, Inc., 473 U. S. 432, 450 (1985); see also ante, at 553 (opinion of Barrett, J.) (recognizing that “an individual law ` “inexplicable by anything but ani- mus” ' is unconstitutional”). 604 UNITED STATES v. SKRMETTI

ments in an evolving feld,” ante, at 525. The concurrences, too, warn that applying intermediate scrutiny in this case may “require courts to oversee all manner of policy choices normally committed to legislative discretion,” including in “areas of legitimate regulatory policy . . . ranging from access to restrooms to eligibility for boys' and girls' sports teams.” Ante, at 551, 553 (opinion of Barrett, J.); see also ante, at 528 (Thomas, J., concurring) (highlighting the potential for “ `high-cost, high-risk lawsuit[s]' ”). Looking carefully at a legislature's proffered reasons for acting, as our equal protec- tion precedents demand, is neither needless “second-guess- [ing],” ante, at 524 (majority opinion), nor judicial encroach- ment on “areas of legitimate regulatory policy,” ante, at 553 (opinion of Barrett, J.). After all, “ `closely scrutiniz[ing] legislative choices' ” is exactly how courts distinguish “legiti- mate regulatory polic[ies]” from discriminatory ones. Ibid. Indeed, judicial scrutiny has long played an essential role in guarding against legislative efforts to impose upon indi- viduals the State's views about how people of a particular sex (or race) should live or look or act. Women, it was once thought, were not suited to attend military schools with men. Virginia, 518 U. S., at 520–523, 540–541. Men and women, others said, should not marry those of a different race. Lov- ing, 388 U. S., at 4. Those laws, too, posed politically fraught and contested questions about race, sex, and biology. In a passage that sounds hauntingly familiar to readers of Tennessee's brief, Virginia argued in Loving that, should this Court intervene, it would fnd itself in a “bog of conficting scientifc opinion upon the effects of interracial marriage, and the desirability of preventing such alliances, from the physi- cal, biological, genetic, anthropological, cultural, psychologi- cal and sociological point of view.” Brief for Appellee in Loving v. Virginia, O. T. 1966, No. 395, p. 7. “In such a situation,” Virginia continued, “it is the exclusive province of the Legislature of each State to make the determination for its citizens as to the desirability of a policy of permitting Cite as: 605 U. S. 495 (2025) 605

or preventing such [interracial] alliances—a province which .the judiciary may not constitutionally invade.” Id., at 7–8. This Court, famously, rejected the States' invitation in Loving to “defer to the wisdom of the state legislature” based on assertions that “the scientifc evidence is substan- tially in doubt.” 388 U. S., at 8. In considering the consti- tutionality of Virginia's male-only military academy, too, the Court itself assessed the “opinions of Virginia's expert wit- nesses” that “ `[m]ales tend to need an atmosphere of adver- sativeness,' ” while “ `[f]emales tend to thrive in a coopera- tive atmosphere.' ” 518 U. S., at 541. What the Court once recognized as an imperative check against discrimination, it today abandons. Yet the task of ascertaining SB1's constitutionality is a familiar one. Tennessee has proffered an undoubtedly im- portant interest in “protect[ing] the health and welfare of minors” by prohibiting medical procedures that carry “risks and harms.” Tenn. Code Ann. §§ 68–33–101(a), (b)–(e); see New York v. Ferber, 458 U. S. 747, 756–757 (1982) (States' “interest in `safeguarding the physical and psychological well-being of a minor' ” is “ `compelling' ”). All, including the Solicitor General, agree that the State may strictly regu- late access to cross-sex hormones and puberty blockers to achieve that purpose. See Tr. of Oral Arg. 39–40, 152–153 (agreeing that West Virginia's more tailored limitations on gender-affrming care would likely survive intermediate scrutiny). It may well be, too, that “[d]eference to legisla- tures” is “particularly critical” in this context, where the provision of medical care to minors is at issue. Ante, at 547 (opinion of Thomas, J.). But that does not change the Court's obligation, as mandated by our precedents, to deter- mine whether the challenged sex classifcation in SB1's cate- gorical ban is tailored to protecting minors' health and wel- fare, or instead rests on unlawful stereotypes about how boys and girls should look and act. See Virginia, 518 U. S., at 533. Infusing that antecedent legal question with a host of 606 UNITED STATES v. SKRMETTI

evidence relevant only to the subsequent application of judi- cial scrutiny, as Justice Thomas would have us do, see ante, at 530–546, simply puts the cart before the horse. The present record offers reason to question (as the Dis- trict Court did) whether Tennessee's categorical ban on treating gender dysphoria bears the “requisite direct, sub- stantial relationship” to its interest in protecting minors' health. Mississippi Univ. for Women v. Hogan, 458 U. S. 718, 725 (1982). Tennessee has offered little evidence, for example, that it is more dangerous to receive puberty block- ers to “identify with, or live as, a purported identity incon- sistent with the minor's sex” than to treat other conditions like precocious puberty.16 Why, then, does SB1 proscribe the regulated medications to treat gender dysphoria, while leaving them available for myriad other purposes? So too is it diffcult to ignore that Tennessee professes concern with protecting the health of minors while categorically banning gender-affrming care for even those minors exhibiting the most severe mental-health conditions, including suicidality. The majority's choice to avoid applying intermediate scru- tiny is all the more puzzling, however, because this Court need not itself resolve these questions or wade into what it dubs the “ferce scientifc and policy debates about the safety, effcacy, and propriety of medical treatments in an evolving feld.” Ante, at 525. The Sixth Circuit never even asked whether the challenged sex classifcation in SB1 “ `serves “im- portant governmental objectives” ' ” or is “ `substantially re- 16 Justice Thomas urges that “[a] discussion of puberty blockers' risks . . . should not exclude the risks presented by cross-sex hormones” because, at present, many “gender dysphoric children treated with pu- berty blockers progress to cross-sex-hormone treatment.” Ante, at 534, n. 4. But the fact that many transgender adolescents currently receive both puberty blockers and cross-sex hormones does not preclude States from regulating access to cross-sex hormones more stringently than access to puberty blockers. Nor does it excuse the State from its obligation to establish that its categorical ban on each type of medication is, in fact, tailored to protecting minors' health and welfare. Cite as: 605 U. S. 495 (2025) 607

Kagan, J., dissenting

lated to the achievement of those objectives.” ' ” Virginia, 518 U. S., at 533. All the United States requested of this Court was confrmation that intermediate scrutiny applied. Brief for United States 32. On remand, the courts could have taken due account of the “[r]ecent developments” that (according to the majority) “underscore the need for legisla- tive fexibility in this area,” including a recent report from England's National Health Service on the use of puberty blockers and hormones to treat transgender minors. Ante, at 524. Yet the majority inexplicably refuses to take even the modest step of requiring Tennessee to show its work before the lower courts.

* * * This case presents an easy question: whether SB1's ban on certain medications, applicable only if used in a manner “inconsistent with . . . sex,” contains a sex classifcation. Because sex determines access to the covered medications, it clearly does. Yet the majority refuses to call a spade a spade. Instead, it obfuscates a sex classifcation that is plain on the face of this statute, all to avoid the mere possibility that a different court could strike down SB1, or categorical healthcare bans like it. The Court's willingness to do so here does irrevocable damage to the Equal Protection Clause and invites legislatures to engage in discrimination by hiding blatant sex classifcations in plain sight. It also authorizes, without second thought, untold harm to transgender children and the parents and families who love them. Because there is no constitutional justifcation for that result, I dissent.

Justice Kagan, dissenting. For all the reasons Justice Sotomayor gives, Tennessee's SB1 warrants heightened judicial scrutiny. See ante, at 585– 603 (dissenting opinion). That means the law survives if, but only if, its sex-based classifcations are “substantially related to the achievement” of “important governmental objectives.” 608 UNITED STATES v. SKRMETTI

United States v. Virginia, 518 U. S. 515, 533 (1996). As Jus- tice Sotomayor notes, the point of applying that test is to smoke out “invidious” or otherwise unfounded discrimina- tion. Ante, at 587; Michael M. v. Superior Court, Sonoma Cty., 450 U. S. 464, 469 (1981) (plurality opinion). More con- cretely put, heightened scrutiny reveals whether a law is based on “overbroad generalizations,” stereotypes, or preju- dices, or is instead based on legitimate state interests, such as the one here asserted in protecting minors' health. Vir- ginia, 518 U. S., at 533. Because the Court is wrong in not subjecting SB1 to that kind of examination, I join Parts I through IV of Justice Sotomayor's dissent. I take no view on how SB1 would fare under heightened scrutiny, and therefore do not join Part V. The record evi- dence here is extensive, complex, and disputed, and the Court of Appeals (because it applied only rational-basis re- view) never addressed the relevant issues. Still more, both the plaintiffs and the Government asked this Court not to itself apply heightened scrutiny, but only to remand that in- quiry to the lower courts. So I would both start and stop at the question of what test SB1 must satisfy. As Justice Sotomayor shows, it is heightened scrutiny. I respect- fully dissent. Reporter’s Note

The attached opinion has been revised to refect the usual publication and citation style of the United States Reports. The revised pagination makes available the offcial United States Reports citation in advance of publication. The syllabus has been prepared by the Reporter of Decisions for the convenience of the reader and constitutes no part of the opinion of the Court. A list of counsel who argued or fled briefs in this case, and who were members of the bar of this Court at the time this case was argued, has been inserted following the syllabus. Other revisions may include adjustments to formatting, captions, citation form, and any errant punctuation. The following additional edits were made:

p. 571, last line: “lead” is changed to “plurality”