(1) ESTABLISHMENT OF PROGRAM.—The normal retirement benefit or pension payable to a retiree who becomes a member of any retirement system or plan and who has not previously participated in such plan, on or after January 1, 1980, shall not exceed 100 percent of his or her average final compensation. However, nothing contained in this section shall apply to supplemental retirement benefits or to pension increases attributable to cost-of-living increases or adjustments. For the purposes of this section, benefits accruing in individual participant accounts established under the Public Employee Optional Retirement Program established in part II of chapter 121 are considered supplemental benefits. As used in this section, the term “average final compensation” means the average of the member’s earnings over a period of time which the governmental entity has established by statute, charter, or ordinance.
(2) RESTRICTION.—No member of a retirement system or plan covered by this part who is not now a member of such plan shall be allowed to receive a retirement benefit or pension which is in part or in whole based upon any service with respect to which the member is already receiving, or will receive in the future, a retirement benefit or pension from a different employer’s retirement system or plan. This restriction does not apply to social security benefits or federal benefits under chapter 67, Title 10, United States Code.