Opinion by Judge TASHIMA; Concurrence by Judge WU.
TASHIMA, Circuit Judge:
Mary Bray (“Bray”) appeals the district court’s judgment affirming the Commissioner of Social Security’s (“Commissioner”) final decision denying her application for social security disability insurance benefits and supplemental security income under Titles II and XVI of the Social Security Act. 42 U.S.C. §§ 401^34, 1381-1383Í. Bray contends that the administrative law judge (“ALJ”) failed to make findings concerning whether she possesses “transferable skills” as Social Security Ruling (“SSR”) 82-^41 expressly requires. Bray also argues that the ALJ erred in discounting her testimony, disregarding a treating physician’s medical opinion, and failing to account for her mental impairments in determining her residual functional capacity. Lastly, Bray contends that the ALJ applied the governing Medical Vocational Guidelines “mechanically” in a borderline situation in violation of 20 C.F.R. § 404.1563(b), by including her in [1221]*1221the 50-54 age category even though she was less than a month from turning 55 at the time of the ALJ’s decision.
We have jurisdiction under 28 U.S.C. § 1291, and we hold that the ALJ erred by failing to make findings on the issue of whether Bray possessed transferable skills. We thus reverse and remand.
BACKGROUND
On March 25, 2003, Bray filed an application for disability insurance benefits alleging that she had been disabled since November 9, 2001. After her claim was denied initially and on reconsideration, Bray requested a hearing before an ALJ. On November 7, 2003, Bray protectively filed for supplemental social security income payments, and that application was consolidated with her prior claim and expedited to the hearing level.
On March 22, 2005, the date of her hearing, Bray was 54 years old and approximately a month from turning 55. She has a high school education and one year’s vocational training as a medical assistant. She suffers from chronic obstructive pulmonary disease (“COPD”), asthma, hypertension, anxiety, depression, and arthritis. Most recently, before filing her application, Bray worked for an ill friend as a part-time caregiver; before that she briefly worked at a call center handling customer service inquiries, but was terminated after three weeks on the job when she requested workplace accommodations related to her difficulty breathing. Subsequently, she enrolled in a custodial training program, but dropped out of the program after three weeks due to difficulty keeping pace and tolerating exposure to chemical fumes. Bray worked as a grocery clerk from August 2002 to January 2003, as a medical assistant from 1993 to 2001, and as an insurance underwriter from 1986 to 1991. She has been unable to hold a full-time job for more than six months since losing her medical assistant position in 2001; thus, the ALJ determined that she had not engaged in “substantial gainful activity” since the onset date of her alleged disability.1
At her hearing, Bray testified that she cannot walk more than half a block without stopping to catch her breath or making use of an inhaler or nebulizer. She also offered a written prescription from a treating physician, issued on May 13, 2004, limiting her to four hours of work per day, five days a week. The physician wrote the prescription after Bray visited the emergency room reporting a flare up of her COPD. A physician with the Oregon Disability Determination Service (“DDS”) evaluated Bray’s physical condition and concluded that she was capable of standing or walking for six hours out of an eight-hour work day and sitting six hours out of an eight-hour work day.
The ALJ found Bray’s testimony regarding her symptoms to be “not entirely credible” due to inconsistencies with record evidence of her daily activities, treatment history, and objective medical condition. The ALJ also discounted the prescription limiting Bray to four hours of work per day, concluding that the limitation was inconsistent with evidence in Bray’s medical record. Relying in large part on the DDS physician’s assessment, [1222]*1222the ALJ constructed Bray’s residual functional capacity (“RFC”), i.e., her ability to work after accounting for her verifiable impairments. The ALJ also determined that Bray’s employment history had provided her with “previous skilled work experience.” A vocational expert (“VE”) testified that a person with Bray’s RFC, age, education, and work experience could find work as a general clerk, file clerk, or sales clerk (all “semiskilled” jobs), and that such jobs were available in significant numbers in both the national and regional economies.2 Relying on the VE’s opinion, the ALJ determined that Bray was capable of performing a modified range of light work and found her not disabled.
The Social Security Administration (“SSA”) Appeals Council denied Bray’s petition for review, making the ALJ’s order the final agency order. Bray then commenced this action in the district court, which affirmed the ALJ’s order. Bray timely appealed.
STANDARD OF REVIEW
We review a district court’s judgment upholding the denial of social security benefits de novo. Tackett v. Apfel, 180 F.3d 1094, 1097 (9th Cir.1999). “We may set aside a denial of benefits only if it is not supported by substantial evidence or is based on legal error.” Robbins v. Soc. Sec. Admin., 466 F.3d 880, 882 (9th Cir.2006). “Substantial evidence means more than a mere scintilla but less than a preponderance; it is such relevant evidence as a reasonable mind might accept as adequate to support a conclusion.” Andrews v. Shalala, 53 F.3d 1035, 1039 (9th Cir.1995). “Where the evidence as a whole can support either a grant or a denial, we may not substitute our judgment for the ALJ’s.” Massachi v. Astrue, 486 F.3d 1149, 1152 (9th Cir.2007) (internal quotation marks omitted).
DISCUSSION
ALJs are to apply a five-step sequential review process in determining whether a claimant qualifies as disabled.3 Bowen v. Yuckert, 482 U.S. 137, 140-42, 107 S.Ct. 2287, 96 L.Ed.2d 119 (1987); 20 C.F.R. §§ 404.1520, 416.920. The burden of proof is on the claimant at steps one through four, but shifts to the Commissioner at step five. See Tackett, 180 F.3d at 1099. If the ALJ determines that a claimant is either disabled or not disabled at any step in the process, the ALJ does not continue on to the next step. See 20 C.F.R. § 416.920(a)(4).
The first step is not at issue. Both Bray and the Commissioner agree that Bray is not currently performing substantial gainful work. See 20 C.F.R. § 416.920(a)(4)(i). At steps two and three, the ALJ found that Bray’s COPD and her depression and anxiety were severe impairments, but that neither corresponded to the listed impairments in the regulations. See 20 C.F.R. § 404.1520(d). Bray does not challenge this finding.
Between steps three and four, the ALJ must, as an intermediate step, assess the [1223]*1223claimant’s RFC. See 20 C.F.R. § 416.920(e). Bray contests the ALJ’s construction of her RFC. At step four the ALJ must determine whether, in light of the claimant’s RFC, she can return to substantial gainful activity performed in the past. 20 C.F.R. § 404.1520(e). The ALJ determined that Bray was not capable of returning to her past relevant work as a medical assistant or insurance underwriter, and neither party disputes that finding. At step five, the Commissioner must establish that the claimant is capable of performing substantial gainful work.4
The ALJ stated Bray’s RFC in this way:
The claimant has the [RFC] to lift 20 pounds occasionally and 10 pounds frequently. She can stand and walk 6 hours out of an 8-hour day and sit 6 hours out of an 8-hour day. She can occasionally climb. She should avoid concentrated exposure to respiratory irritants. She is able to carry out, attend and concentrate on all but the most detailed and complex tasks.
The ALJ presented the above statement to the VE, who then considered whether an individual burdened with the stated limitations could obtain gainful work in the national economy. The VE testified that Bray could not return to gainful work in her former capacity as a medical assistant or underwriter, but that she had transferable skills and could transition to work as a general clerk, file clerk, or sales clerk. Accordingly, the ALJ determined that Bray is not disabled.
I. The ALJ’s Failure to Follow SSR 82-41
Relying on SSR 82-41, Bray contends that the ALJ committed reversible error when he assumed that Bray possessed transferable skills without making specific findings in support of that assumption. SSR 82-41 states, in relevant part:
When the issue of skills and their transferability must be decided, the ... ALJ is required to make certain findings of fact and include them in the written decision. Findings should be supported with appropriate documentation.
When a finding is made that a claimant has transferable skills, the acquired work skills must be identified, and specific occupations to which the acquired work skills are transferable must be cited in the ... ALJ’s decision.... It is important that these findings be made at all levels of adjudication to clearly establish the basis for the determination or decision for the claimant and for a reviewing body including a Federal district court.
SSR 82^1, 1982 WL 31389, at *7. The ALJ found that Bray has “previous skilled work experience,” but made no finding as to the transferability of any acquired skills. The decision does not identify the particular skills that Bray possesses, nor does it explain the basis for the determination that she possesses skilled work experience.
[1224]*1224At Bray’s hearing, the VE testified that Bray’s experience as an insurance underwriter — approximately fifteen years prior to the hearing date — had exposed her to computers,5 customer service, and possibly some data entry, and that her work as a medical assistant may also have exposed her to similar skills. It is impossible to discern whether the VE’s brief commentary represents the sole basis for the ALJ’s assumption that Bray had transferable skills. The decision is similarly silent on the issue of whether the particular skills that the VE identified would be transferable in Bray’s case given her age and medical impairments. See SSR 82-41, at *2 (“[A] person has no special advantage if he or she is skilled or semiskilled but can qualify only for an unskilled job because his skills cannot be used to any significant degree in other jobs.”).
Moreover, the Guidelines state that “[i]n order to find transferability of skills to skilled sedentary work for individuals who are of advanced age (55 and over), there must be very little, if any, vocational adjustment required in terms of tools, work processes, work settings, or the industry.” 20 C.F.R. pt. 404, subpt. P, app. 2 § 201.00(f). The skills that the VE cited at the hearing derived from Bray’s work as an insurance underwriter more than fifteen years earlier. Neither the ALJ’s decision nor the VE’s testimony addresses whether Bray — who was one month from turning 55 at the time of her hearing— would have to undergo more than minimal “vocational adjustment” to perform successfully the tasks required of a file clerk, general clerk, or sales clerk, or otherwise determined whether the skills required of an insurance underwriter are substantially similar to those required of a general, file, or sales clerk.
SSRs, according to the governing regulations, “are binding on all components of the Social Security Administration” and “represent precedent final opinions and orders and statements of policy and interpretations” of the SSA.6 20 C.F.R. § 402.35(b)(1); see also Heckler v. Edwards, 465 U.S. 870, 873 n. 3, 104 S.Ct. 1532, 79 L.Ed.2d 878 (1984) (noting the function of SSRs). “SSRs reflect the official interpretation of the [SSA] and are entitled to ‘some deference’ as long as they are consistent with the Social Security Act and regulations.” Avenetti v. Barnhart, 456 F.3d 1122, 1124 (9th Cir.2006) (quoting Ukolov v. Barnhart, 420 F.3d 1002, 1005 n. 2 (9th Cir.2005)). SSRs do not carry the “force of law,” but they are binding on ALJs nonetheless. See Quang Van Han v. Bowen, 882 F.2d 1453, 1457 & n. 6 (9th Cir.1989).
The Commissioner concedes that the ALJ did not follow the express requirements of SSR 82-41, but argues that the SSR is not applicable in this case. Citing a Sixth Circuit opinion for support, the Commissioner argues that SSR 82-41 does not require specific findings when the ALJ relies on the testimony of a VE to determine whether a claimant has transferable skills. See Wilson v. Comm’r of Soc. Sec., 378 F.3d 541, 549-50 (6th Cir.2004). In Wilson, the Commissioner argued that SSR 82-41 requires specific findings only when the ALJ relies exclusively on the grids to reach a determination. See id. at 549. The court concluded that the Commissioner’s reading of SSR 82-41 was entitled to substantial deference and that the [1225]*1225proffered interpretation was reasonable. Id. at 549-50.
For the reasons set forth below, however, we believe the Second Circuit’s opinion in Draegert v. Barnhart, 311 F.3d 468 (2d Cir.2002), offers a sounder approach. In Draegert, the court held that specific findings on transferable skills are necessary even where the ALJ relies on the testimony of a YE. See id. at 475-77; see also Botefur v. Heckler, 612 F.Supp. 973, 976-77 (D.Or.1985) (concluding that specific findings under SSR 82-41 are required when the ALJ relies on a VE’s testimony).
In Auer v. Robbins the Supreme Court held that an agency’s interpretation of its own regulations, even when the interpretation is adopted as a position in litigation, is entitled to substantial deference. 519 U.S. 452, 462-63, 117 S.Ct. 905, 137 L.Ed.2d 79 (1997). The Auer opinion implies that, in order to receive substantial deference, an agency’s interpretation must represent its “fair and considered judgment,” rather than a position that is merely convenient in a given dispute. See 519 U.S. at 462, 117 S.Ct. 905 (citing Bowen v. Georgetown Univ. Hosp., 488 U.S. 204, 212, 109 S.Ct. 468, 102 L.Ed.2d 493 (1988)); Bigelow v. Dep’t of Def., 217 F.3d 875, 878-79 (D.C.Cir.2000) (Tatel, J., dissenting) (stating that no deference is due “where there is reason to suspect” that an agency’s interpretation of its own regulation represents a “convenient litigation position” rather than an expression of the agency’s “fair and considered judgment”).
Even granting a large measure of interpretive deference, the Commissioner’s reading of SSR 82-41 strains credulity. The SSR does not qualify its application, stating only that “[w]hen the issue of skills and their transferability must be decided, the ... ALJ is required to make certain findings of fact and include them in the written decision. Findings should be supported with appropriate documentation.” SSR 82-41, 1982 WL 31389, at *7 (emphasis added); see also Christensen v. Harris County, 529 U.S. 576, 588, 120 S.Ct. 1655, 146 L.Ed.2d 621 (2000) (holding that no deference is due under Auer where the underlying regulation is unambiguous). Further, the SSR states that “[cjonsultation with a[YE] may be necessary to ascertain” whether a given skill or set of skills are transferable in a claimant’s particular case. SSR 82-41, 1982 WL 31389, at *4. Thus, the SSR presumes that ALJs will be relying on expert testimony to determine whether a claimant has transferable skills, and it makes little sense to interpret the SSR’s provision requiring specific written findings as inapplicable whenever an expert is involved. It is the ALJ, and not the YE, who is responsible for making findings.
According to the district court, the ALJ’s assumption that Bray had transferable skills was sufficiently reviewable. Adopting the Sixth Circuit’s logic, the district court explained that “in the absence of supplementary testimony from a vocational expert, the ALJ would be obligated to specifically include a finding related to transferable skills” but where the ALJ relies on an expert, “the source of evidence regarding transferable skills is apparent and reviewable by the court.” The district court then concluded that “it was correct for the [VE] to assume that Bray had some degree of computer skill.” This is precisely the sort of finding, however, that SSR 82-41 requires the ALJ, and not the court, to make. Long-standing principles of administrative law require us to review the ALJ’s decision based on the reasoning and factual findings offered by the ALJ — ■ not post hoc rationalizations that attempt to intuit what the adjudicator may have been thinking. See SEC v. Chenery Corp., 332 U.S. 194, 196, 67 S.Ct. 1575, 91 L.Ed. [1226]*12261995 (1947) (“[I]n dealing with a determination or judgment which an administrative agency alone is authorized to make, [courts] must judge the propriety of such action solely by the grounds invoked by the agency. If those grounds are inadequate or improper, the court is powerless to affirm the administrative action by substituting what it considers to be a more adequate or proper basis.”); Snell v. Apfel 177 F.3d 128, 134 (2d Cir.1999) (“The requirement of reason-giving exists, in part, to let claimants understand the disposition of their cases.... ”).
The ALJ’s departure from established SSA procedure thwarts this court’s ability to determine whether or not Bray possesses transferable skills — a dispositive issue for her claim. Cf. Chiappa v. Sec’y of Dep’t of Health, Educ. & Welfare, 497 F.Supp. 356, 358 (S.D.N.Y.1980) (“The failure of ALJs to make [specific] findings in disability cases is among the principal causes of the delay and uncertainty ... in this area of the law.”). The district court chose to review the transferable skills finding based on what it assumed the ALJ to have determined, but meaningful review of an administrative decision requires access to the facts and reasons supporting that decision. See Chenery, 332 U.S. at 196, 67 S.Ct. 1575. SSR 82-41 articulates this principle in a clear form. The ALJ erred in disregarding the regulation and the district court erred in disregarding the underlying principle.
We thus remand this case to the Commissioner so that the ALJ can further develop the record and make specific findings on whether Bray has transferable skills.7 See Terry v. Sullivan, 903 F.2d 1273, 1280 (9th Cir.1990) (holding that this Court has discretion to remand for further fact finding, if the record is unclear as to a claimant’s entitlement to disability benefits).
II. The Residual Functional Capacity Determination
The ALJ’s non-disability finding flowed from the presentation of a hypothetical RFC to a VE, who then identified specific jobs Bray could perform. Bray contests the representativeness of the ALJ’s hypothetical by challenging three predicate findings: 1) that Bray’s testimony regarding the severity of her symptoms was not entirely credible; 2) that a treating physician’s prescription note was not entirely credible; and 3) that severe, medically determinable mental impairments notwithstanding, Bray is “able to carry out, attend and concentrate on all but the most detailed and complex tasks.” We agree with the district court that substantial evidence supports the ALJ’s construction of Bray’s RFC.
1. Bray’s Testimony
The ALJ found that Bray’s description of her symptoms was not entirely credible. Specifically, the ALJ discounted Bray’s statement that she is incapable of walking more than half a block without stopping to catch her breath and using a nebulizer or inhaler, that she is unable to lift twenty pounds, and that she cannot carry as much as ten pounds “very far.” Substantial evidence supports the ALJ’s decision to give limited weight to Bray’s characterization of her symptoms.
If an ALJ finds a claimant’s characterization of his or her own symptoms [1227]*1227unreliable, the ALJ must make a credibility determination backed up by specific findings. See Bunnell v. Sullivan, 947 F.2d 341, 345 (9th Cir.1991). “[0]nee the claimant produces objective medical evidence of an underlying impairment, an adjudicator may not reject a claimant’s subjective complaints based solely on a lack of objective medical evidence to fully corroborate” the claimant’s allegations. Id. In reaching a credibility determination, an ALJ may weigh inconsistencies between the claimant’s testimony and his or her conduct, daily activities, and work record, among other factors. See Light v. Soc. Sec. Admin., 119 F.3d 789, 792 (9th Cir.1997).
The ALJ made specific findings in support of his decision to discount Bray’s testimony, noting that: 1) Bray continued to smoke cigarettes up until one month before her hearing, despite complaining of debilitating shortness of breath and acute chemical sensitivity; 2) she leads an active lifestyle, including cleaning, cooking, walking her dogs, and driving to appointments; 3) she recently worked as a personal caregiver for two years, and has sought out other employment since then; 4) she reported to an evaluating physician that she only becomes wheezy when engaging in heavy exertion, and on other occasions reported that her COPD was “going fine”; and 5) Bray’s statements at her hearing do not comport with objective evidence in her medical record. The above findings are supported by the record, and belie Bray’s claim of debilitating respiratory illness.
Bray maintains that it was improper for the ALJ to cite her continued smoking as adversely impacting her credibility. See Shramek v. Apfel, 226 F.3d 809, 812-13 (7th Cir.2000) (noting, in dicta, that nicotine’s addictive properties made it “extremely tenuous” to discredit a claimant’s description of her impairments based on the claimant’s continued smoking). The ALJ reasoned that if Bray’s respiratory ailments were as severe as she claimed, she would likely refrain from smoking. It is certainly possible that Bray was so addicted to cigarettes that she continued smoking even in the face of debilitating shortness of breath and acute chemical sensitivity. Even so, the ALJ presented four other independent bases for discounting Bray’s testimony, and each finds ample support in the record. Thus, the ALJ’s reliance on Bray’s continued smoking, even if erroneous, amounts to harmless error. See Batson v. Comm’r of Soc. Sec. Admin., 359 F.3d 1190, 1197 (9th Cir.2004) (concluding that, even if the record did not support one of the ALJ’s stated reasons for disbelieving a claimant’s testimony, the error was harmless).
2. The Treating Physician
Bray contends that the ALJ erred in elevating contrary evidence above the opinion of a treating physician. At her hearing, Bray introduced a prescription written by Dr. Seyer, limiting her daily work activity to four hours per day, five days a week. In contrast, the DDS physician that evaluated Bray’s physical impairments reported that Bray was capable of occasionally lifting twenty pounds, frequently lifting ten pounds, standing or walking for six hours out of an eight-hour work day, and sitting six hours out of an eight-hour work day.
The ALJ gave several reasons for granting Dr. Seyer’s prescription note “little weight”: 1) the note was written at Bray’s specific request; 2) Bray’s medical records reveal that she only experiences severe shortness of breath after heavy exertion and not in conjunction with the usual activities of daily living; 3) Dr. Seyer’s prescription was written after an exacerbation of her COPD; and 4) Bray did not seek [1228]*1228medical treatment again for eight months after Dr. Seyer wrote the prescription, suggesting a lack of need for a continued limitation of her work hours.
A treating physician’s opinion is entitled to “substantial weight.” Embrey v. Bowen, 849 F.2d 418, 422 (9th Cir.1988). When evidence in the record contradicts the opinion of a treating physician, the ALJ must present “specific and legitimate reasons” for discounting the treating physician’s opinion, supported by substantial evidence. Lester v. Chater, 81 F.3d 821, 830 (9th Cir.1995).8 However, “[t]he ALJ need not accept the opinion of any physician, including a treating physician, if that opinion is brief, conclusory, and inadequately supported by clinical findings.” Thomas v. Barnhart, 278 F.3d 947, 957 (9th Cir.2002).
Bray argues that the ALJ’s stated reasons are neither legitimate nor sufficient to justify discounting Dr. Seyer’s prescription note. Specifically, Bray contends that the fact that Dr. Seyer wrote the note at her request is not a legitimate reason for disbelieving it, because a treating physician would not prescribe medically unwarranted restrictions. As the district court noted, however, the treating physician’s prescribed work restrictions were based on Bray’s subjective characterization of her symptoms. As the ALJ determined that Bray’s description of her limitations was not entirely credible, it is reasonable to discount a physician’s prescription that was based on those less than credible statements.
3. Consideration of Bray’s Mental Impairments
If an ALJ finds a severe impairment at step two, that impairment must be considered in the remaining steps of the sequential analysis. 20 C.F.R. §§ 404.1523, 416.923. The ALJ found that Bray possessed two severe impairments — COPD and an adjustment disorder (i.e., symptoms of anxiety and depression). Bray argues that the ALJ failed to account for her adjustment disorder in the final construction of her RFC, and thus ran afoul of the governing regulations. Hypothetical questions posed to a VE must “set out all the limitations and restrictions of the particular claimant....” Russell v. Sullivan, 930 F.2d 1443, 1445 (9th Cir.1991). If an ALJ’s hypothetical does not reflect all of the claimant’s limitations, then “the expert’s testimony has no evidentiary value to support a finding that the claimant can perform jobs in the national economy.” DeLorme v. Sullivan, 924 F.2d 841, 850 (9th Cir.1991).
The ALJ adequately accounted for Bray’s adjustment disorder in his construction of her RFC and in the hypothetical he presented to the VE. He asked the VE to assume that Bray could “carry out, attend [sic] and concentrate on all but the most detailed and complex tasks.” Bray argues that this statement contradicts the ALJ’s earlier finding at step two that Bray’s mental impairments were “severe.” She posits that a severe impairment, by definition, inhibits a claimant from engaging in “basic work activities,” and the ALJ’s statement of her RFC does not capture that limitation. Bray offers no authority to support the proposition that a [1229]*1229severe mental impairment must correspond to limitations on a claimant’s ability to perform basic work activities.
More importantly, the medical record supports the ALJ’s conclusions that Bray’s mental impairments prevented her from completing only the most complex tasks. In constructing Bray’s RFC, the ALJ relied on the opinion of Dr. Krishnan, a psychiatrist who evaluated Bray in August of 2003. Dr. Krishnan concluded that:
The claimant can accept instructions from supervisors and interact with coworkers and the public. The claimant will be able to perform work activities on a consistent basis without special or additional supervision. The claimant would likely be able to maintain regular attendance in the workplace, as she is currently working. She is able to complete a normal workday/workweek without interruptions from her psychiatric condition. She also would be able to deal with the usual stress encountered in competitive work.
Bray does not offer evidence to controvert Dr. Krishnan’s assessment, and the ALJ’s conclusion that Bray can “carry out, attend and concentrate on all but the most detailed and complex tasks” represents a reasonable finding, grounded in the administrative record.
CONCLUSION
The ALJ assumed that Bray had transferable skills, but failed to articulate a clear basis to support that assumption, contrary to the requirement of SSR 82-41. As a result, this Court cannot properly determine whether substantial evidence supports the ALJ’s decision finding Bray not disabled. The issue of transferability of skills is dispositive, as Bray is now 58 years old, and thus should be considered in the “advanced age” category. According to the grids, a 58-year-old with Bray’s limitations who lacks transferable skills qualifies as disabled.9
We reverse the judgment of the district court and remand the case with instructions that it further remand this case to the Commissioner for further proceedings consistent with this opinion.
REVERSED and REMANDED.