Mich. Comp. Laws § 38.13b
A member who retires on or after October 1, 1979 shall have his or her credited service include credit for service rendered by him or her between October 1, 1971 and October 1, 1979 to a joint federal-state commission authorized under the public works and economic development act of 1965, Public Law 89-136, 79 Stat. 552, in which the member represented this state and for which at least 50% of the member's salary was derived from funds provided by this state, if the member pays into the employees' savings fund a contribution determined by the board, but not less than an amount equal to 5% of the member's full-time compensation for the fiscal year in which payment is made, for each year of service claimed, and if the member relinquishes all rights in and to any pension benefit he or she would be eligible to receive from another publicly supported pension plan as the result of that service.
MCL 38.13b