Madsen, J.
The personal representative of decedent Margaret O. Burns and the co-personal representatives of decedent Doris R. Wheeler dispute the State’s recovery, under former RCW 43.20B.140, for preenactment or pre-amendment medical care benefits, provided to the decedents during their lifetimes. The trial courts in both cases issued summary judgment in favor of the Estates. The Court of Appeals reversed. We find that recovery of preen-actment or preamendment benefits constitutes improper [107]*107retroactive application of the statute and reverse the Court of Appeals.
STATEMENT OF THE CASE
Michael Olver is the personal representative for the estate of Margaret O. Burns. From March 1986, until her death in 1993, Ms. Burns received medical care benefits from the Department of Social and Health Services (DSHS). In 1987, Washington enacted a provision authorizing DSHS to recover the cost of medical care benefits from the recipient’s estate after her death. See former RCW 43.20B.140. When Ms. Burns died in 1993, DSHS filed a claim against her estate for reimbursement of all benefits she had received starting in 1986. The amount of the claim was $17,259.31. The personal representative allowed DSHS to recover only the benefits paid after the statute’s enactment in 1987. DSHS therefore recovered only $10,034.02.
DSHS sued the Burns Estate to recover the preenactment benefits. The parties stipulated to the facts and filed cross motions for summary judgment. The trial court granted the Estate’s motion. The Court of Appeals reversed and instructed the trial court to enter judgment in favor of DSHS.
Richard T. Wheeler and James A. Wheeler are co-personal representatives for the estate of their mother, Doris R. Wheeler. Between June 1991 and her death on August 16, 1993, Ms. Wheeler received $49,604.18 in medical benefits from the State. Ms. Wheeler left her entire estate, with total assets of $73,000, to her two adult children. When Ms. Wheeler started receiving benefits the recovery statute allowed a $50,000 exemption if any children survived the beneficiary. Beyond this exempted amount, the statute permitted DSHS to claim up to 35 percent of remaining estate assets. Former RCW 43.20B.140(l)(c). On July 25, 1993, approximately one month before Ms. Wheeler died, the Legislature eliminated [108]*108the $50,000 exemption and allowed only $2,000 set aside for personal property. Laws of 1993, ch. 272, § 2. Between the effective date of this amendment and her death, Ms. Wheeler received $791.34 in medical benefits.
After Ms. Wheeler died, DSHS filed a claim against the Wheeler Estate for $49,604.18. DSHS argues that the 1993 amendment eliminating the $50,000 exemption applies to all estates arising after the amendment’s effective date. In contrast, the Estate argues that even when an estate arises after that date, the amendment does not apply to preen-actment benefits. The Estate therefore calculated the Department’s recovery for benefits received before July 25, 1993, according to the preamendment statute. With the $50,000 exemption, and 35 percent cap on remaining estate assets, DSHS recovered $8,000 ($73,000 - 50,000 = 23,000 x 35% = $8,000).
In addition to the $8,000 amount, the Wheeler Estate also allowed the Department to recover $791.34 for benefits received after July 25, 1993. The Estate later paid the full amount claimed by DSHS to avoid accruing interest, and counterclaimed for a refund. The parties filed cross motions for summary judgment. The trial court entered judgment in favor of the Wheeler Estate. The Court of Appeals reversed in an unpublished opinion.
The Burns Estate challenges the application of RCW 43.20B.140; whereas, the Wheeler Estate challenges the application of the statute’s amendment at RCW 43.20B.140(l)(c). Both cases, however, present the same central issue of whether these provisions apply to preen-actment or preamendment benefits. This court granted review in In re Estate of Burns, No. 63616-8, on April 9, 1996. In re Estate of Wheeler, No. 63713-0, was consolidated with Burns on May 8, 1996.
DISCUSSION
In 1982, Congress enacted the Tax Equity and Fiscal Responsibility Act (TEFRA), which gives the states sev[109]*109eral optional methods of recovering payments for medical care. These methods give the states access to the home equity of Medicaid recipients. In 1987, Washington chose one of these methods by adding a new section, RCW 74.09.750, under "Revenue Recovery Procedures Revised for the Department of Social and Health Services.” Laws of 1987, ch. 283, § 13. The new section was later recodified as former RCW 43.20B.140. Until July 1993, when the Legislature eliminated the $50,000 exemption in RCW 43.20B.140(l)(c), the statute provided in relevant part:
(1) The department is authorized to recover the cost of medical care provided to a recipient who was sixty-five years or older, upon the recipient’s death except:
(a) Where there is a surviving spouse; or
(b) Where there is a surviving child under 21 years of age or blind or disabled as defined in the state plan under Title XIX of the social security act; or
(c) To the extent of the first fifty thousand dollars of the estate value at the time of death, where there are surviving children other than as defined above, and not to exceed thirty-five percent of the remainder.
(2) The department may assert and enforce a claim against the estate of the deceased recipient for the debt in subsection (1) of this section, in accordance with chapter 11.40 RCW.
(3) The remedies in subsection (2) of this section are nonexclusive and upon the death of the recipient, the department shall have a lien for the debt in subsection (1) of this section. The lien attaches to the real property of which the deceased recipient was seized immediately before death. Upon subsequent filing of the notice . . . the lien shall be deemed to relate back and be effective against such property as of the date of the recipient’s death. Recovery under the lien shall be upon the sale or transfer of the subject property.
Former RCW 43.20B.140.
In 1993, the Legislature replaced the $50,000 exemption with the following language:
For family heirlooms, collectibles, antiques, papers, [110]*110jewelry, photos, or other personal effects that have been held in the possession of the deceased recipient to which a surviving child may otherwise be entitled not to exceed a total fair market value of two thousand dollars.
RCW 43.20B.140(l)(c).1
As a general rule, courts presume that statutes operate prospectively unless contrary legislative intent is express or implied. Macumber v. Shafer, 96 Wn.2d 568, 570, 637 P.2d 645 (1981); Baker v. Baker, 80 Wn.2d 736, 741, 498 P.2d 315 (1972); Pape v. Department of Labor & Indus., 43 Wn.2d 736, 741, 264 P.2d 241 (1953); In re Cascade Fixture Co., 8 Wn.2d 263, 272, 111 P.2d 991 (1941). Courts disfavor retroactivity because of the unfairness of impairing a vested right or creating a new obligation with respect to past transactions. Landgraf v. USI Film Prods., 511 U.S. 244, 114 S. Ct. 1483, 1500, 128 L. Ed. 2d 229 (1994); Id. at 1505 (stating that a statute has a genuinely retroactive effect if it impairs rights a party possessed when he acted, increases his liability for past conduct, or imposes new duties with respect to completed transactions); In re Cascade Fixture Co., 8 Wn.2d at 272 (stating that retroactive legislation changing vested rights is not favored); Adcox v. Children’s Orthopedic Hosp. & Med. Ctr., 123 Wn.2d 15, 30, 864 P.2d 921 (1993) (declining to apply a statute retroactively because it created a new civil penalty for noncomplying hospitals). Elementary considerations of fairness dictate that individuals should have an opportunity to know what the law is and to conform their conduct accordingly. Landgraf, 114 S. Ct. at 1497.
A statute operates prospectively when the precipitating event for operation of the statute occurs after enactment, even when the precipitating event originated in a [111]*111situation existing prior to enactment. Aetna Life Ins. Co. v. Washington Life & Disability Ins. Guar. Ass’n, 83 Wn.2d 523, 535, 520 P.2d 162 (1974); Landgraf, 114 S. Ct. at 1499 (stating that "[a] statute does not operate 'retrospectively’ merely because it is applied in a case arising from conduct antedating the statute’s enactment ... or upsets expectations based in prior law”). A statute "is not retroactive merely because it relates to prior facts or transactions where it does not change their legal effect.” State v. Bel-garde, 119 Wn.2d 711, 722, 837 P.2d 599 (1992) (quoting State v. Scheffel, 82 Wn.2d 872, 879, 514 P.2d 1052 (1973), appeal dismissed, 416 U.S. 964 (1974)); Landgraf, 114 S. Ct. at 1499.
The parties in this case agree that the language of RCW 43.20B.140 shows that the Legislature intended only prospective application of the statute. They disagree, however, as to what that means. DSHS contends that the statute and its amendment operate prospectively so long as they apply only to estates created after the provisions’ effective dates, 1987 and 1993 respectively, because the legal obligations fall only upon the estates and not the recipients. The statute clearly permits the State to collect payment only upon the recipient’s death. Therefore, the Department argues, liability arises only after creation of the estates. Furthermore, the statute and its amendment are applicable only if no spouse or children are living when the estates arise. Thus, the "precipitating event” is the creation of the estate.
The Estates argue that DSHS’s interpretation gives the provisions retroactive effect when they apply to preenactment or preamendment benefits because they attach new legal consequences to the decedents’ acceptance of benefits. Specifically, the provisions grant new rights to DSHS and impair the vested rights of recipients. The Burns Estate argues that application of the statute to pre-1987 benefits grants the State a claim of reimbursement and a right to a lien which did not exist before 1987. Application of the statute thereby imposes duties upon Ms. [112]*112Burns that did not exist when she applied for and received the benefits. Similarly, the Wheeler Estate argues that application of the 1993 amendment impairs the right to receive medical assistance without encumbering a portion of estate assets with an obligation to repay. The recovery statute thus imposes new legal ramifications on the completed transaction of giving and receiving benefits.
The Estates also argue that the preenactment or pre-amendment acceptance of benefits "creates the liability” for which the State now seeks to collect. Br. of Resp’t (Burns) at 19; Supplemental Br. of Dep’t (Wheeler) at 7. Thus, the acceptance of benefits is the precipitating event for application of the statute. If the recovery statute retroactively attaches liability to the acceptance of benefits, then the liability necessarily would be that of the decedent, and not merely that of the estate. Accordingly, the Wheeler Estate argues that an estate is not a legal entity separate from a person, but a word that describes a person’s property before and after death.
To determine which activity the challenged provisions regulate, we turn to the plain language of the statute. Section 2 discusses the State’s right to recover benefit payments as a "debt” owed by the Medicaid recipient. Section 3 allows the State to collect payment by imposing a lien on the recipient’s estate. According to the plain language of the statute, the regulated activity is the creation of debt and the collection of such debt by imposing claims or liens on recipients’ estates.
DSHS argues, however, that the statute does not regulate repayment of debts owed by Medicaid recipients because the statute imposes liability only on their estates. The Department maintains that the statute clearly contemplates recovery from probate estates and not from recipients themselves. However, the time of payment upon a recipient’s death does not change the regulated activity from creation and collection of a debt to disposition of an estate.
In a prior case, this court held that although a debt is [113]*113payable only upon death, the time of payment does not change the debt into something testamentary in character. In re Estate of Krueger, 11 Wn.2d 329, 336, 119 P. 312 (1941) (holding that the payment of a contractual obligation was not a testamentary transfer even though it was payable at the time of the obligor’s death); Gostina v. Whitham, 148 Wash. 72, 74, 268 P. 132 (1928) (stating that an "instrument founded upon a consideration, whereby one agrees to pay another a definite sum, does not partake of a testamentary character simply because the time of payment be postponed until death.”). Thus, although recipients pay off their debts to the State only upon their deaths, the purpose of the challenged provisions is to regulate the collection of debts owed by Medicaid recipients, not the disposition of their estates.
Rather than rely on principles regarding debts and liens, the Department mistakenly relies on a case involving inheritance taxes. Specifically, the State relies on a prior statement by this court that the state’s ability to take taxes and exactions from a decedent’s estate rests on the principle that a state "may, if it so chooses, take to itself the whole of [estate] property . . . without regard to the wishes or direction of the person who died possessed of it . . . .” In re Estate of Sherwood, 122 Wash. 648, 654, 211 P. 734 (1922).
Initially, general statements such as the one quoted above are to be confined to the facts and issues of that particular case. State ex rel. Wittier v. Yelle, 65 Wn.2d 660, 670, 399 P.2d 319 (1965). Furthermore, the State has broad powers of taxation. Therefore, taxation of the transfer of a decedent’s property is significantly different from imposition of a claim or lien on an estate. The State has "plenary power over inheritance taxation; it is within the legislature’s power to prescribe the nature, kind, extent and amount of such taxes, and to what degree the estate or the heirs may be taxed ... as conditions of bequeathing, devising and inheriting property.” In re Estate of Toomey, 75 Wn.2d 915, 919, 454 P.2d 420 (1969) [114]*114(citing In re Estate of Sherwood, 122 Wash. 648, 211 P. 734 (1922)).
The Department’s recovery for benefits upon a recipient’s death is unlike inheritance taxation. With inheritance taxes, the amount of the estate property received by the inheritor determines the amount owed to the State. See Sherwood, 122 Wash. at 659 (discussing the principle that an inheritance tax is leviable on the amount of property actually received). Here, however, the amount of Medicaid benefits received during one’s lifetime determines the amount of the Department’s recovery. Therefore, the State’s reliance on cases involving inheritance taxes is misplaced.
Because RCW 43.20B.140 regulates the collection of debts through imposition of a claim or lien, principles regarding debts, liabilities, and liens govern interpretation of the statute. These principles are useful for interpreting § 6 of the 1993 amendment, which states that the act "does not have the effect of terminating or in any way modifying any liability, civil or criminal, that is already in existence on the effective date of this act.” Laws of 1993, ch. 272, § 6.
Because the statute does not define "debt,” "liability,” or "lien,” we consider the general definitions of these terms. Liability is a broad term that can have comprehensive significance, including contingent responsibility. Black’s Law Dictionary 914 (6th ed. 1990). Although a debt, which is a "fixed and certain obligation to pay money or some other valuable thing,” is not as broad a term as liability, it similarly can mean an obligation to make payment "either in the present or in the future.” Id. at 403. See also Feminist Women’s Health Ctr. v. Codispoti, 118 Wn.2d 99, 103, 821 P.2d 1198 (1991) (stating that under certain circumstances the concept of "debt” has very broad meaning). The definitions of "debt” and "liability” vary according to the statute in which the terms are used. Id. at 103 (discussing the definition of "debt”).
A lien is an encumbrance upon property as security for [115]*115payment of a debt. Sullins v. Sullins, 65 Wn.2d 283, 285, 396 P.2d 886 (1964); Kinne v. Kinne, 27 Wn. App. 158, 161, 617 P.2d 442 (1980), review denied, 95 Wn.2d 1001 (1981); Anderson v. Grays Harbor County, 49 Wn.2d 89, 91, 297 P.2d 1114 (1956). In other words, a lien is not a debt, but a remedy for a debt. Nelson v. Nelson Neal Lumber Co., 171 Wash. 55, 61, 17 P.2d 626, 92 A.L.R. 554 (1932). In the instant cases, the lien becomes effective on the date of the recipient’s death. Therefore, the lien must be a remedy for a debt that existed prior to that date.
With respect to Ms. Wheeler, the Department argues that the preexisting liability in the Laws of 1993, ch. 272, § 6 refers only to present obligations of reimbursement. However, the language of § 6 prohibits "any” modification of any preexisting liability, indicating that the Legislature intended a broad meaning for "liability.” See Rettkowski v. Department of Ecology, 128 Wn.2d 508, 515, 910 P.2d 462 (1996) (interpreting the plain language "[a]ny person feeling aggrieved by any decision . . . .’’to mean that RCW 90.14.190 broadly applied to any person feeling aggrieved by any water resource decision of the Department of Ecology). Further, the "liability, . . . already in existence on the effective date of [the] act,” must refer to the liability for repayment of preamendment benefits because the statute refers to no liability other than the "debt” for reimbursement created in subsection (1). Laws of 1993, ch. 272, § 6. Therefore, § 6 prohibits modification of Ms. Wheeler’s liability existing prior to enactment of the 1993 amendment.
In summary to this point, the statutory provisions at issue regulate the collection of a debt. They do so by characterizing the benefits received as a debt contingent upon existence of assets of a recipient at death, and by authorizing recovery by DSHS of that debt from those assets. The precipitating event is, therefore, the receipt of the benefits giving rise to the contingent indebtedness, and not the creation of the decedent’s estate.
The State contends, however, that these cases are analo[116]*116gous to Aetna Life, where the statute at issue was held to apply prospectively despite drawing upon antecedent facts for its application. In Aetna Life, a statute required insurers wanting to do business in this state to become members of a guaranty association and to pay an assessment if a fellow insurer received a liquidation order. Aetna Life, 83 Wn.2d at 534-35. The insurers argued that the statute applied retroactively when the State collected an assessment on premiums received before its enactment. Id. This court held, however, that the statute attached no new legal consequences to the preenactment collection of premiums. The court rejected the retroactivity argument because the liquidation order for a fellow insurer, not the receipt of premiums, precipitated application of the statute. Id.
Contrary to the State’s contention, Aetna Life is quite unlike the present case. In Aetna Life, the assessment on preenactment premiums did not change the legal nature of the transaction between insurers and the policyholders who had paid the premiums. By contrast, applying the statutes to allow recovery for preenactment benefits would change the legal nature of the transaction between DSHS and those who accepted Medicaid benefits. The benefits, when received, did not rise to a contingent debt. Whereas DSHS had no claim for reimbursement before the statute’s enactment, the Department would have a claim against the recipient through her estate if the statute applies as the State argues. The new claim would affect a property right which in effect "vested” when recipients received the benefits.2
In contrast, this court has declined to apply a statute when doing so would have impaired vested rights and thus would have given the statute in question retroactive effect. For example, in In re F.D. Processing, Inc., 119 Wn.2d [117]*117452, 463, 832 P.2d 1303 (1992), this court declined to apply a 1991 amendment to RCW 60.13.010 that impaired a bank’s interest in collateral which became vested when the bank perfected its interest in 1989. Similarly, in Mie-bach v. Colasurdo, 102 Wn.2d 170, 181, 685 P.2d 1074 (1984), this court declined to apply a provision establishing notice requirements to property owners whose property was to be sold at a sheriffs sale. The court declined to apply the provision retroactively because it would have impaired a right in the property which became vested when the sheriff sent an order of confirmation. Id. The court noted that even a remedial statute will not be applied retroactively if it affects a substantive or vested right. Id.
We also note that recipients who know of the new legal consequence, which the statutes at issue attach to receipt of benefits, have the choice whether to accept the benefits knowing that recovery may be had from their estate. This possibility is a realistic consideration because Washington’s medical care program pays for medical needs ranging from minor to life-threatening.3 However, recipients of benefits paid before enactment of the statutory provisions would have had no such choice. Application of the statutory provisions in their cases therefore would, as the Estates and Amicus Curiae argue, result in the unfairness for which courts traditionally have disfavored retroactivity. See Landgraf, 114 S. Ct. at 1500 (stating that the unfairness of imposing new burdens on persons after the [118]*118fact justifies the presumption against statutory retroactivity). Application of the provisions would deprive Ms. Wheeler and Ms. Burns of the opportunity to decide whether to accept benefits based upon knowledge of reimbursement requirements. See Br. of Resp’t (Burns) at 24; Br. of Amicus Curiae at 3, 9-10.
The State responds that the recipients could have replanned their estates or redistributed their assets after enactment of the provisions. See In re Estate of Burns, 79 Wn. App. 558, 904 P.2d 301, review granted, 129 Wn.2d 1003 (1995). However, replanning one’s estate would not have resolved the fact that the recipient had already accepted benefits that would have to be repaid to the State under the State’s theory.4
The contrast between the instant cases and State v. Scheffel illustrates the unfairness of applying the challenged provisions to preenactment benefits. State v. Schef-fel, 82 Wn.2d 872, 514 P.2d 1052 (1973), appeal dismissed, 416 U.S. 964 (1974). In Scheffel, the challenged statute allowed license revocation for anyone who received three or more convictions for certain offenses within a five-year period. Id. at 875. This court permitted application of the statute to the two defendants in that case even though each had accrued two convictions prior to the act’s effective date. Id. at 878. Enactment of the statute put the defendants on notice that they would be classified as habitual offenders if they accrued one more violation within the statutory period. Id. Thus, the defendants could have avoided operation of the statute by refraining from committing additional violations. Id. at 878-79. In contrast to Scheffel, Ms. Wheeler and Ms. Burns could not refrain [119]*119from dying in order to avoid operation of RCW 43.20B.140. The statute cannot be retroactively applied to impose upon them a contingent liability for reimbursement of benefits received before the statute’s enactment, payable once they died.
Finally, the State argues that the policy of maintaining the viability of the medical care program favors its interpretation of the statute. In order to continue providing medical care to needy persons, the State should be able to recoup benefits once a recipient dies. The policy is unfair, however, when the State attempts to apply it to benefits given prior to enactment of the reimbursement provisions.
While decisions from other jurisdictions are not binding, it is of interest that the Supreme Courts of California and Arkansas reached conflicting results when they interpreted recovery statutes similar to RCW 43.20B.140. The deeply divided (4-3 decision) California Supreme Court held that the Department of Health Services could recover the cost of Medi-Cal benefits paid prior to the effective date of the recovery statute when the recipient died after the statute took effect. Kizer v. Hanna, 48 Cal. 3d 1, 767 P.2d 679, 682, 255 Cal. Rptr. 412 (1989). The Kizer court concluded that such an interpretation did not give the statute retroactive effect. Id. at 686. By contrast, the Arkansas Supreme Court unanimously held that the Department of Human Services could not recover Medicaid payments given prior to the effective date of the recovery statute even though the recipient died after the statute took effect. Estate of Wood v. Arkansas Dep’t of Human Servs., 319 Ark. 697, 894 S.W.2d 573 (1995). A contrary interpretation would give the statute retroactive application by permitting it to affect a decedent’s vested rights. Id. at 576.
The Arkansas decision applies the rules on retroactivity discussed above. Before enactment, the recipient reasonably would have considered the benefits to be an entitlement. Id. at 576. After enactment, the recipient had a debt payable upon her death. Id. Payment for this debt [120]*120would come out of estate assets, along with all the other debts incurred by the decedent during her lifetime. We agree with the Arkansas Supreme Court and three justices of the California Supreme Court who decided that equivalent recovery statutes transformed the recipient’s property right in the Medicaid payments already received into a loan to be repaid from estate assets. See Estate of Wood, 894 S.W.2d at 576; Kizer, 767 P.2d at 688.
CONCLUSION
RCW 43.20B.140 and its amendment apply prospectively and cannot be applied retroactively to impose on Medicaid recipients new obligations with respect to past transactions with the State Department of Social and Health Services. We reverse the Court of Appeals and reinstate the judgment of the trial court. We do not reach the Estates’ remaining arguments regarding due process and the contract clause.5
Smith, Guy, Johnson, and Alexander, JJ., concur.