with whom OP ALA, Justice, joins, dissenting:
¶ 1 I dissent with this Court’s decision holding that section 67.13a of title 72 does not require municipalities to credit retirees for military service.
¶ 2 Section 67.13a provides:
War veterans, as defined above, shall receive maximum benefits available for each year of creditable service, not to exceed five (5) years, for active military service for retirement benefits in the retirement systems within the State of Oklahoma....
(Emphasis added.) The Court recognizes that the plain language of section 67.13a covers municipal retirement plans. However, the Court reasons that the plain language is in direct conflict with section 48-102 of title 11, and, thus, the plain language does not control.
¶3 When construing statutes, the cardinal rule is to determine the legislative intent. Nelson v. Pollay, 1996 OK 142, ¶ 6, 916 P.2d 1369, 1373. ‘Where the language of a statute is plain and unambiguous, and its meaning clear and no occasion exists for the application of rules of construction, the statute will be accorded the meaning as expressed by the language therein employed.” Cave Springs Public School Dist. I-30 v. Blair, 1980 OK 103, ¶ 4, 613 P.2d 1046. In this case, the Court did not need to look further *335than the plain language. Even so, statutes addressing retirement benefits are to be liberally construed in favor of the public employee. See Allen v. State of Oklahoma ex rel. Board of Trustees of the Oklahoma Uniform Retirement System for Justices and Judges, 1988 OK 99, 769 P.2d 1302; Dangott v. ASG Industries, Inc., 1976 OK 131, ¶ 12, 558 P.2d 379, 382. The plain language of the statute and a liberal construction of the phrase “within the State of Oklahoma” leads to the conclusion that the Oklahoma Legislature intended section 67.13a to apply to municipal employees. Further, the fact that section 67.13a is found under the sections on Soldiers and Sailors does not diminish its force and validity. Green v. Green, 309 P.2d 276, 278, 1957 OK 70.
¶ 4 I do not find that section 67.13a conflicts with section 48-102 of title 11. The City of Tulsa (City) has elected to provide retirement benefits to its employees pursuant to the enabling provisions of sections 48-101 to 48-106 of title 11 of the Oklahoma Statutes. Tulsa, Okla., Ordinances tit. 28, ch. 1, § 100. Under section 48-101 of title 11, municipalities are allowed, but not required, to provide retirement benefits for their employees. Section 48-102 provides for a municipal retirement fund to be supported at the city’s discretion by contributions from the municipality or joint contributions of the city and the employee. Under sections 48-101 through 48-106, the city is given authority to set the limit on the amount of benefits to be paid to the employee, to determine the amount of its contributions, to set the amount of the employee’s contributions, and to determine the persons eligible for retirement benefits.
¶5 I agree that the enabling act gives broad discretion to the City of Tulsa. This control given municipalities over retirement plans is not exclusive. It is subject to other state statutes, such as section 67.13a. Northeastern Oklahoma Building and Construction Trades Council v. Tulsa Metropolitan Water Auth., 1974 OK 14, 519 P.2d 488; Town of Mannford v. Watson, 1964 OK 110, 394 P.2d 506.
¶ 6 In Northeastern Oklahoma Building and Construction Trades Council, 1974 OK 14, ¶ 15, 519 P.2d at 488, this Court held that because Tulsa was a public body, a construction contract was subject to the prevailing wage statute. In Watson, 1964 OK 110, 394 P.2d at 506, this Court held that attorneys could not recover from the City of Mannsford under contingent fee contract without proof the fee complied with statutory requirements. Thus, under this state’s ease law, City contracts are subject to applicable statutory provisions.
¶ 7 The City recognized its need to conform to state statutory as well as ease law in section 300 of the Municipal Employees’ Retirement Plan. Section 300 provides: “The Employer shall make contributions to the Fund in such amounts and at such times as shall be necessary to provide the benefits set forth herein and in accordance with the provisions of any law applicable to the Plan.” (Emphasis added.) Thus, under the ordinance which contains the terms of the contract between its employees and the City, the contract is subject to “any law applicable to the Plan.” Since section 67.13a is applicable to the retirement plan, the employment contract is subject to the provisions of section 67.13a.
¶ 8 Contrary to Tulsa’s argument, the application of section 67.13a to municipalities does not unconstitutionally impair Tulsa’s and its employees’ contract. The laws in effect at the time a contract is made are considered part of the contract. McDermott v. Bennett, 395 P.2d 566, 570, 1964 OK 197. The legislature may modify public employees’ pension rights; even though the rights are contractually based, so long as the modifications are reasonable and necessary and provide offsetting advantages to the disadvantages. Taylor v. State and Education Employees Group Insurance Program, 1995 OK 51, ¶ 13, 897 P.2d 275, 279. Thus, section 67.13a was ,a part of the plaintiffs employment contract, and the legislature had authority to modify the contract.
¶ 9 A past employee of the City whose retirement benefits are vested have contractual rights in the retirement plan. Taylor, 1995 OK 51, ¶ 14, 897 P.2d at 279. These vested rights are protected from modifications in the Plan. Okla. Const, art. II, § 15; *336Taylor, .1995 OK 51, ¶ 13, 897 P.2d at 279. However, the state may make modifications.to the plan as long as the modifications are reasonable and necessary, serve an important public purpose, and do not impair the actuarial soundness of the fund. Taylor, 1995 OK 51, ¶ 14, 897 P.2d at-279.
¶ 10 In Taylor, the legislature passed a statute transferring $39,600,000 from the Teachers Retirement System of Oklahoma to the Education Employees Group Insurance Reserve Fund. This Court upheld the transfer against an attack that the transfer was unconstitutional in that it violated article II, section 15. This Court reasoned that the transfer was -reasonable and necessary, served an important public policy, and did not compromise the integrity of the retirement system.
¶ 11 Under the City’s retirement plan, an employee contributes a percentage of earning to the plan. Tulsa, Okla., Ordinances tit. 28, ch. 3, § 301. The City is required to “make contributions to the Fund in such amounts and at such times as shall be necessary to provide the benefits set forth herein and in accordance with the provision of any law applicable to the Plan.” Id. at § 300 (emphasis added). Because section 67.13a of title 72 of the Oklahoma Statutes was applicable to the retirement plan, the City was required to make contributions in an amount sufficient to cover the additional benefits for military credit. Thus, the retirees whose rights had vested when the amendment to section 67.13a became effective should not suffer a reduction in their benefits because the City failed to meet its obligations to the retirement plan.
¶ 12 A finding that section 67.13(a) applies to municipalities would require an analysis of whether the decision’s application is prospective only. In determining whether a decision is limited to prospective application, this Court will weigh three - factors: (1) whether the decision establishes a new' principal of law, (2) “whether retrospective operation will further or retard [the statute’s] operation,” and (3) whether the decision “could produce substantial inequitable results if applied retroactively.” Chevron Oil Company v. Huson, 404 U.S. 97, 106-07, 92 S.Ct. 349, 355, 30 L.Ed.2d 296 (1971); Kay Electric Cooperative v. State ex rel. Oklahoma Tax Comm’n, 1991 OK 76, ¶ 4, 815 P.2d 175, 177.
¶ 13 In Campbell v. White, 1993 OK 89, 856 P.2d 255, this Court gave prospective effect to its ruling “to avoid needless disruption to the operation of state agencies.” In Campbell, this Court invalidated the functional approach taken by the Legislature in enacting legislation as violative of the single-subject rule of art. 5, section 56 of the Oklahoma Constitution. Because retrospective application of the decision would have resulted in disruption of state agencies due to lack of funding, this Court determined that the decision should be applied prospectively only.
¶ 14 The record is insufficient to determine the effect of applying 67.13(a) on the functioning of the City in the present ease. I would remand the matter with an instruction to the trial court to take evidence on this issue, to determine the extent to which the functions of the City would be impaired, and to determine whether the effect of applying section 67.13(a) to municipalities should only be applied prospectively.