No ex post facto law, bill of attainder nor law impairing the obligation of contracts shall be enacted by the legislature.

ANNOTATIONS

Comparable provisions. — Idaho Const., art. I, § 16.

Iowa Const., art. I, § 21.

Montana Const., art. II, § 31.

Utah Const., art. I, § 18.

Wyoming Const., art. I, § 35.

Prohibition against ex post facto laws in this section is not at issue with amendment to 66-8-102 NMSA 1978 by House Bill 117 (Laws 2003, Ch. 90) and House Bill 278 (Laws 2003, Ch. 164) because House Bill 117 went into effect immediately under its emergency clause. State v. Smith, 2004-NMSC-032, 136 N.M. 372, 98 P.3d 1022, rev'g 2004-NMCA-026, 135 N.M. 162, 85 P.3d 804.

The prohibition against ex post facto laws does not apply to sanctions that are remedial in nature. — The constitutional prohibition against ex post facto laws is violated when a statute involving retroactivity is passed that makes criminal a previously innocent act, increases the punishment, or changes the proof necessary to convict the defendant. A statute or regulation is considered retroactive if it impairs vested rights acquired under prior law or requires new obligations, imposes new duties, or affixes new disabilities to past transactions. The constitutional prohibition on ex post facto laws applies only to penal statutes that disadvantage the offender affected by them; the prohibition does not apply to penalties that are considered remedial in nature. Whether a sanction constitutes punishment is determined by evaluating the government’s purpose in enacting the legislation, rather than evaluating the effect of the sanction on the defendant. Yepa v. N.M. Taxation & Revenue Dep’t, 2015-NMCA-099, cert. denied, 2015-NMCERT-008.

Where defendant was arrested for aggravated DWI and his license was revoked in 2008, and where defendant became eligible for license reinstatement in March of 2009, but he did not apply for reinstatement of his license until late July 2009, after the effective date of the 2009 amendment to 66-5-33.1 NMSA 1978, which amended the statutory license reinstatement requirements to include a minimum of six months of driving with an ignition interlock device before reinstatement of a revoked license, the district court erred in concluding that the motor vehicle division’s application of the 2009 amendment constituted a violation of the constitutional prohibition against ex post facto laws, because the license revocation provision of the Implied Consent Act serves the legitimate non-punitive purpose of protecting the public from the dangers presented by drunk drivers and helps enforce regulatory compliance with the laws governing the licensed activity of driving; the revocation of a person’s driver’s license based on the conduct of either failing a blood-alcohol test or refusing to take a chemical test is consistent with the government’s goals in implementing the Implied Consent Act and is therefore remedial, not punitive. Yepa v. N.M. Taxation & Revenue Dep’t, 2015-NMCA-099, cert. denied, 2015-NMCERT-008.

The Fraud Against Taxpayers Act is predominantly remedial in nature and does not violate ex post facto principles. — The ex post facto clause prohibits retroactive application of penal legislation. The prohibition does not apply to penalties that are considered remedial in nature. The Fraud Against Taxpayers Act (FATA), 44-9-1 NMSA 1978 et seq., is predominantly remedial in nature; the specific legislative designation of FATA proceedings and penalties as “civil” indicate that the legislature intended to craft a civil statute, and not a single section of FATA specifies or punishes criminal conduct; the civil penalties and treble damages under FATA are predominantly compensatory and serve remedial purposes by encouraging qui tam plaintiffs to expose fraud and corruption in state government and by offsetting the costs incurred by the government. State ex rel. Foy v. Austin Capital Mgmt., Ltd., 2015-NMSC-025, aff’g in part, rev’g in part, 2013-NMCA-043, 297 P.3d 357.

The retroactive application of the Fraud Against Taxpayers Act is constitutional. — Because the treble damages under The Fraud Against Taxpayers Act (FATA), 44-9-1 NMSA 1978 et seq., are predominantly compensatory and remedial in nature, they do not violate the ex post facto clause of the United States constitution or the New Mexico constitution and may be applied retroactively. The New Mexico supreme court declined to determine whether the civil penalties under FATA, although they possess predominantly compensatory purposes, may be applied retroactively because the district court had not yet awarded a definitive civil penalty. State ex rel. Foy v. Austin Capital Mgmt., Ltd., 2015-NMSC-025, aff’g in part, rev’g in part, 2013-NMCA-043, 297 P.3d 357.

Sex Offender Registration and Notification Act does not violate either the federal or state ex post facto clause. State v. Druktenis, 2004-NMCA-032, 135 N.M. 223, 86 P.3d 1050.

Sex offender registration. — Because the Albuquerque Sex Offender Registration and Notification Act ordinance is a regulatory scheme that is not punitive in intent or effect, the retroactive application of the ordinance does not violate the ex post facto clause. ACLU v. City of Albuquerque, 2006-NMCA-078, 139 N.M. 761, 137 P.3d 1215.

Retroactive application of Sex Offender Registration and Notification Act (Chapter 29, Article 11A NMSA 1978) does not violate the New Mexico constitution’s ex post facto clause. State v. Druktenis, 2004-NMCA-032, 135 N.M. 223, 86 P.3d 1050.

Prohibition applies to judicial rulemaking. — A state constitutional prohibition on legislative enactments applies equally to judicial rulemaking. State v. Norush, 1982-NMCA-034, 97 N.M. 660, 642 P.2d 1119, cert. denied, 98 N.M. 50, 644 P.2d 1039.

Jury instructions. — Jury instructions which deprive an accused of a defense available at the time of his act are prohibited as ex post facto. State v. Norush, 1982-NMCA-034, 97 N.M. 660, 642 P.2d 1119, cert. denied, 98 N.M. 50, 644 P.2d 1039.

Withdrawal of six-month rule. — The retroactive withdrawal of the six-month rule from Rule 5-604 NMRA, which is a procedural rule, is not an unconstitutional ex post facto law under the United States Constitution. State v. Romero, 2011-NMSC-013, 150 N.M. 80, 257 P.3d 900.

Substitution of punishments permissible. — Statute substituting electrocution for hanging, and applicable to those under sentence of hanging on effective date of the statute, was not ex post facto. Woo Dak San v. State, 1931-NMSC-056, 36 N.M. 53, 7 P.2d 940.

Age confinement must end under Children's Code . — The constitutional prohibition against ex post facto laws prevents the courts from applying the Children's Code (Chapter 32A NMSA 1978) adopted in 1993 to permit the confinement of a child until he or she reaches the age of twenty-one where the delinquent acts and original adjudication occurred while the prior code was in effect. State v. Adam M., 1998-NMCA-014, 124 N.M. 505, 953 P.2d 40.

Denial or obstruction of contract rights. — Statute which denies or obstructs preexisting contract rights is constitutionally objectionable even though it professes to act only upon the remedy. Rubalcava v. Garst, 1949-NMSC-035, 53 N.M. 295, 206 P.2d 1154, opinion partly superseded and case remanded for inclusion of indispensable parties, 1952-NMSC-057, 56 N.M. 647, 248 P.2d 207.

Oral adoption contract. — Law requiring written agreement of adoption to maintain claim against decedent's estate based upon adoption contract is not applicable to oral contract made and performed prior to its effective date. Rubalcava v. Garst, 1949-NMSC-035, 53 N.M. 295, 206 P.2d 1154, opinion partly superseded and case remanded for inclusion of indispensable parties, 1952-NMSC-057, 56 N.M. 647, 248 P.2d 207.

Existing contracts are subject to the legitimate exercise of the police power, and a sign ordinance is a legitimate exercise of the city's police power. Thus, such an ordinance does not unconstitutionally impair the obligation of a contract. Temple Baptist Church, Inc. v. City of Albuquerque, 1982-NMSC-055, 98 N.M. 138, 646 P.2d 565.

Alteration of contract by providing cost-of-living increases. — The governor's veto of cost-of-living increases, included in the general fund appropriation, for certain private employees of community based providers of mental health services who had contracted with the health and environment department, was valid. The legislature may not attempt to alter the terms of existing contractual relationships through the appropriation process. State ex rel. Coll v. Carruthers, 1988-NMSC-057, 107 N.M. 439, 759 P.2d 1380.

The Energy Transition Act does not impair contractual or vested rights. — Where the public regulation commission (Commission) gave leave for the public service company of New Mexico (PNM) to issue energy transition bonds of up to $361,000,000 in connection with the abandonment of its interests in the San Juan generating station units one and four and to collect separate and non-bypassable energy transition charges from its customers in repayment of the bonds, pursuant to the Energy Transition Act (ETA), §§ 62-18-1 through 62-18-23 NMSA 1978, and where appellants, two organizations that represent energy consumers, claimed that energy consumers had contractual or vested rights in a modified stipulation between PNM and the Commission with respect to the San Juan generating station and a prior Commission decision to defer review of some issues related to the four corners generating station, and therefore the ETA violates this section by interfering with those rights, appellants' claim is without merit, because appellants have not shown that energy consumers possessed any cognizable contractual or vested rights in the referenced stipulation or Commission decisions. Citizens for Fair Rates & the Env't v. NMPRC, 2022-NMSC-010.

Increase in workmen's compensation benefits. — To give amendment increasing maximum allowable medical benefits under workmen's compensation a retroactive effect would alter a substantial term of the contract existing between employer and employee at the time of injury, contrary to the constitutional provisions prohibiting impairment of contracts. Noffsker v. K. Barnett & Sons, 1963-NMSC-156, 72 N.M. 471, 384 P.2d 1022.

Change in accrual rate of annual vacation leave for public employee. — The personnel board's decision that juvenile probation officers transferred from the judicial branch to the executive branch should accrue annual leave from the time of the transfer at rates specified under regulations for the executive branch and not at the judicial branch rates did not constitute an unconstitutional infringement of the employee's contract rights given that the legislation governing the transfer of the officers did not confer the right, contractual or otherwise, to retain the judicial branch rates of annual leave accrual and also given that statutes fixing the compensation or terms of public employment are presumed merely to establish public policy subject to legislative revision and not to create contractual or vested rights. Whitely v. New Mexico State Personnel Bd., 1993-NMSC-019, 115 N.M. 308, 850 P.2d 1011.

Change of definition that denied sick leave incentive benefit. — Where a collective bargaining agreement permitted employees who were assigned to shift work in a twenty-four hour facility and who did not utilize sick leave for a calendar quarter to receive eight hours of administrative leave; after an arbitrator decided that the sick leave incentive benefit did not apply only to workers who worked an assignment that constituted an unending twenty-four-hour coverage of the job, the state personnel board adopted a regulation that defined "shift work schedule" to be a normal work schedule assigned to an employee as part of a rotating group of individuals that must continuously maintain a twenty-four hour operation; and the union claimed that some state agencies had in the past given the sick leave incentive to workers working in a twenty-four-hour facility even when the workers did not work in a position requiring continuous shifts within a twenty-four-hour period, that the state used the new definition to deny the benefit to workers in jobs that did not require twenty-four-hour coverage, that the board attempted to circumvent the arbitrator's decision by adopting a definition that was the opposite of the definition the arbitrator had adopted, that the regulation denied sick leave incentive pay that the state had contractually agreed to provide and had paid in the past, and that the regulation impaired the agreement in violation of the contract clause of the United States constitution and the New Mexico constitution, the union's complaint adequately pled that the regulation would substantially impair an existing contract right so as to make the regulation unconstitutionally retroactive and stated a cause of action on which relief could be granted. AFSCME Council 18 v. State of N.M., 2013-NMCA-106.

Ratification bonus payable to members of public-sector bargaining unit. — Where a proposed provision of a public-sector collective bargaining agreement provided that upon ratification of the agreement all bargaining unit members would receive a ratification bonus of $500 to be paid by the first pay period after ratification to compensate bargaining unit members for the delay in implementing wage increases under the new agreement; and the bargaining unit members were public employees, Article IV, Section 27 applied to the members of the bargaining unit and payment of the bonus would violate Article IV, Section 27. Nat'l Union of Hosp. & Healthcare Employees v. Board of Regents, 2010-NMCA-102, 149 N.M. 107, 245 P.3d 51, cert. denied, 2010-NMCERT-010, 149 N.M. 64, 243 P.3d 1146.

Payment of bounties earned. — A person earning bounties before law authorizing them was repealed was still entitled to the bounty. Hayner v. Board of Comm'rs, 1924-NMSC-013, 29 N.M. 311, 222 P. 657.

Lease obligations not impaired. — General appropriations bill, Laws 1971, ch. 327, directing that vocational rehabilitation division of the state board of education should relocate its office from lessor's premises to a site more accessible to its clients, did not impair obligations of rental contract which specifically provided that lessee had right to terminate if directed by the legislature to move its offices. National Bldg. v. State Bd. of Educ., 1973-NMSC-053, 85 N.M. 186, 510 P.2d 510.

Retrospective operation of statute prescribing costs. — The fact that enactments awarding attorneys' fees, which are valid exercises of the power to prescribe costs, operate retrospectively will not render them unconstitutional. Cutter Flying Serv., Inc. v. Straughan Chevrolet, Inc., 1969-NMSC-132, 80 N.M. 646, 459 P.2d 350.

Statute of limitations. — In view of saving clause allowing reasonable time for pursuit of actions accruing prior to enactment, 37-1-24 NMSA 1978, providing limitations for suits against cities, towns and villages, was not an unconstitutional impairment of contract. Hoover v. City of Albuquerque, 1954-NMSC-043, 58 N.M. 250, 270 P.2d 386.

Repurchase rights alterable. — Legislature may at any time alter preference rights of former owners to repurchase property which state has acquired upon tax sale, because there is no contract with the former owner and no vested rights are disturbed. Yates v. Hawkins, 1942-NMSC-029, 46 N.M. 249, 126 P.2d 476.

Alteration of bank stockholders' liability. — Where bank stockholders' liability is changed pursuant to N.M. Const., art. XI, § 13, right of legislature to make the change has been reserved by the latter and does not violate this section. Melaven v. Schmidt, 1929-NMSC-100, 34 N.M. 443, 283 P. 900.

Contract with debenture holders. — Statute authorizing refund of gasoline excise taxes only out of surplus not necessary to payment of interest and principal of highway debentures did not impair obligations of contract between state and debenture holders. Streit v. Lujan, 1931-NMSC-062, 35 N.M. 672, 6 P.2d 205, appeal dismissed, 285 U.S. 527, 52 S. Ct. 405, 76 L. Ed. 924 (1932).

Limiting application of revenue. — Former act which limited the application of municipal revenue from public utilities did not impair obligation of contract. Dreyfus v. City of Socorro, 1920-NMSC-035, 26 N.M. 127, 189 P. 878.

Retroactive law valid. — Laws 1923, ch. 140, § 515 (repealed), relating to liens of assessments for conservancy districts, did not violate this section. In re Proposed Middle Rio Grande Conservancy Dist., 1925-NMSC-058, 31 N.M. 188, 242 P. 683.

No vested rights in licenses. — A liquor license is a privilege and not property within the meaning of the due process and contract clauses of state and federal constitutions, and in them licensees have no vested property rights. Baca v. Grisolano, 1953-NMSC-028, 57 N.M. 176, 256 P.2d 792.

A privilege or license to do business in a state is not a contract, and does not vest in the holder thereof the right to enforce the same under constitutional guarantees. Sovereign Camp, W.O.W. v. Casados, 21 F. Supp. 989 (D.N.M.), aff'd, 305 U.S. 558, 59 S. Ct. 79, 83 L. Ed. 352 (1938).

Privilege tax. — Former 2% privilege tax from which qualified benefit societies were exempted did not violate federal constitution, art. I, § 10, nor this section. Sovereign Camp, W.O.W. v. Casados, 21 F. Supp. 989 (D.N.M.), aff'd, 305 U.S. 558, 59 S. Ct. 79, 83 L. Ed. 352 (1938).

Prohibition on enforcement of prepayment penalty. — The prohibition on enforcement of a prepayment penalty in Subsection A of 48-7-19 NMSA 1978 is sufficiently justified by the significant and legitimate public purpose of promoting the alienability of land to withstand challenge under this section. Los Quatros, Inc. v. State Farm Life Ins. Co., 1990-NMSC-082, 110 N.M. 750, 800 P.2d 184.

Taxes pledged for debt. — Former 67-19-3, 1953 Comp., violated this section and U.S. Const., art. I, § 10, cl. 1, insofar as it related to county, school district and municipal taxes, which by the Bateman Act (6-6-11 NMSA 1978) were pledged to the payment of debts arising during the year for which taxes are levied. 1939 Op. Att'y Gen. 39-3127.

Retroactivity, per se, not invalid. — In the absence of an expressed prohibition, a law is not invalid merely because retroactive in operation. 1961 Op. Att'y Gen. No. 61-68.

This constitutional inhibition is applicable to city ordinances as it is to state statutes. 1962 Op. Att'y Gen. No. 62-62.

Ex post facto law defined. — An ex post facto law is defined as one which operating retrospectively and on penal or criminal matters only renders a previously innocent act criminal. 1969 Op. Att'y Gen. No. 69-10.

The scope of the prohibition against ex post facto laws is limited in its application to laws of a criminal nature. 1964 Op. Att'y Gen. No. 64-91.

Bill of attainder defined. — A bill of attainder is defined as a legislative act inflicting punishment without a judicial trial. 1969 Op. Att'y Gen. No. 69-10.

Law requiring corporation to change name invalid. — Name of foreign corporation admitted to do business in state becomes part of its assets, and state contracts that such corporation shall have right to use it and may not require it to be changed, and law attempting to do so is invalid. 1931 Op. Att'y Gen. No. 31-135.

State highway debentures issued under the law of 1933 are valid and are not affected by or subject to a referendum, as such law could not be suspended by referendum petition from which constitution exempts laws providing for preservation of public peace, safety and health, and prohibits enactment of ex post facto law or one impairing obligations of contracts. 1933 Op. Att'y Gen. No. 33-702.

Limitations on change of party affiliation. — A provision which would not preclude one from seeking office, but would merely prevent his changing of party affiliation between its enactment and the next election, would not be an unconstitutional interference with a vested right. 1969 Op. Att'y Gen. No. 69-10.

Am. Jur. 2d, A.L.R. and C.J.S. references. — 16A Am. Jur. 2d Constitutional Law §§ 634, 655, 682.

Retrospective modification of, or refusal to enforce, decree for alimony, separate maintenance, or support, 6 A.L.R.2d 1277, 52 A.L.R.2d 156.

Constitutionality, construction and application of statute or ordinance providing for reduction of pension or retirement benefit of public officer or employee because of independent income, 7 A.L.R.2d 692.

Reforestation: constitutionality of reforestation or forest conservation legislation, 13 A.L.R.2d 1095.

Attachment: contract impairment clause as affecting foreign attachment or garnishment in action by nonresident against nonresident or foreign corporation upon a foreign cause of action, 14 A.L.R.2d 420.

Statutes relating to sexual psychopaths, 24 A.L.R.2d 350.

Constitutionality of statute shifting the burden of federal excise tax, 26 A.L.R.2d 925.

Retrospective operation of legislation affecting estates by the entireties, 27 A.L.R.2d 868.

Derivative action: application to pending action or existing cause of action of statute regulating stockholders' actions, 32 A.L.R.2d 851.

Retrospective application of statute relating to trust investments, 35 A.L.R.2d 991.

Validity of compulsory pooling or unitization statute or ordinance requiring owners or lessees of oil and gas lands to develop their holdings as single drilling unit and the like, 37 A.L.R.2d 434.

Validity of statute or ordinance requiring real estate broker to procure license, 39 A.L.R.2d 606.

Venue statute, retroactive operation and effect of, 41 A.L.R.2d 798.

Construction, application, and effect of constitutional provisions or statutes relating to cumulative voting of stock for corporate directors, 43 A.L.R.2d 1322.

Assertion of immunity as ground for removing or discharging public officer or employee, 44 A.L.R.2d 789.

Cemetery: impairment of obligation of contract by public prohibition or regulation of location of, 50 A.L.R.2d 905.

Pension law modifications, retrospective operation of, 52 A.L.R.2d 437.

Validity of statute making private property owner liable to contractor's laborers, materialmen, or subcontractors where owner fails to exact bond or employ other means of securing their payment, 59 A.L.R.2d 885.

Validity, under state constitutions, of nonsigner provisions of Fair Trade Laws, 60 A.L.R.2d 420.

Usury: constitutionality of retrospective operation of statute denying defense of usury to corporation, 63 A.L.R.2d 929.

Wrongful death, retroactive effect of statute changing manner and method of distribution of recovery or settlement for, 66 A.L.R.2d 1444.

Burial contracts: validity of retrospective operation of statutes regulating preneed contracts for the sale or furnishing of burial services and merchandise, 68 A.L.R.2d 1251.

State succession, transfer, inheritance, or estate tax in respect of life insurance and annuities, 73 A.L.R.2d 157.

Constitutionality of state legislation to reimburse public utilities for cost of relocating their facilities because of highway construction, conditioned upon federal reimbursement of the state under the terms of Federal-Aid Highway Act (23 USC sec. 123), 75 A.L.R.2d 419.

Public pension fund, validity and effect of retroactive change in rate of employee's contribution to, 78 A.L.R.2d 1197.

Validity, and applicability to causes of action not already barred, of a statute enlarging limitation period, 79 A.L.R.2d 1080.

Prospective or retroactive operation of overruling decision, 10 A.L.R.3d 1371.

Long-arm statutes: retrospective operation of state statutes or rules of court conferring in personam jurisdiction over nonresidents or foreign corporations on the basis of isolated acts or transactions, 19 A.L.R.3d 138.

Divorce: retrospective effect of statute prescribing grounds of divorce, 23 A.L.R.3d 626.

Statutory change of age of majority as affecting preexisting status or rights, 75 A.L.R.3d 228.

Validity of statute canceling, destroying, nullifying, or limiting enforcement of possibilities of reverter or rights of re-entry for condition broken, 87 A.L.R.3d 1011.

16A C.J.S. Constitutional Law §§ 277, 392, 411, 429.