Michigan Compiled Laws, Chapter 38. Civil Service and Retirement § 38.1011

Sec. 11. (1) “Service” means the period beginning on January 1 of the year in which the member took office or on the date of the oath of office in the case of a special election, and ending on December 31 of the term to which the member was elected; on the date of termination of service; or the date of death in office, whichever occurs first. Legislative service used to qualify for and receive a retirement allowance under the state employees' retirement act, 1943 PA 240, MCL 38.1 to 38.69, shall not be credited as service for the purpose of this act. A member who qualifies under section 6(b) or (c) may choose to have service credited under this act if the service would otherwise have qualified as service under the state employees' retirement act, 1943 PA 240, MCL 38.1 to 38.69, or if the service was to the state before 1943.

(2) A member who has satisfied the requirements of section 23(1)(a)  1 and who was drafted, enlisted, inducted, or commissioned into active duty with the armed forces of the United States government may elect to receive service credit for not more than 2 years of active duty upon proof of the service having been rendered and upon request and payment to the retirement system of an amount equal to 5% of the member's salary for the calendar year in which payment is made multiplied by the years including any fraction of a year of service that the member elects to purchase up to the maximum. A deferred vested member or retirant who has satisfied the requirements of section 23(1)(a) and who was drafted, enlisted, inducted, or commissioned into active duty with the armed forces of the United States may elect to receive service credit for not more than 2 years of active duty upon proof of the service having been rendered. A deferred vested member or retirant who is electing military service credit under this subsection shall pay an amount equal to 5% of the salary of a member who is serving at the time payment is made multiplied by the number of years including any fraction of a year of service for which the deferred vested member elects to receive credit. Service shall not be credited under this subsection if it is or would be credited under any other federal, state, or local publicly supported retirement system, but this restriction shall not apply to those persons who have or will have acquired retirement eligibility under the federal government for service in the reserve.

(3) Membership in the retirement system created under this act shall not disqualify an employee of a political subdivision of this state from membership in a pension or retirement system established in the political subdivision of this state by reason of the compensation the employee receives from the political subdivision. Membership in the retirement system created under this act shall not affect the benefits to which a member, deferred vested member, retirant, or beneficiary may be entitled under the retirement system established in the political subdivision.