(a) A rate of member or state contributions to or a rate of interest or the rate of a fee required for the establishment of credit in the retirement system may not be reduced or eliminated, a type of service may not be made creditable in the retirement system, a limit on the maximum permissible amount of a type of creditable service may not be removed or raised, a new monetary benefit payable by the retirement system may not be established, and the determination of the amount of a monetary benefit from the system may not be increased, if, as a result of the particular action, the time, as determined by an actuarial valuation, required to amortize the unfunded actuarial liabilities of the retirement system would be increased to a period that exceeds 30 years by one or more years.
(b) If the amortization period for the unfunded actuarial liabilities of the retirement system exceeds 30 years by one or more years at the time an action described by Subsection (a) is proposed, the proposal may not be adopted if, as a result of the adoption, the amortization period would be increased, as determined by an actuarial valuation.