Michigan Compiled Laws, Chapter 38. Civil Service and Retirement § 38.1366

Sec. 66. (1) Except as provided in section 65,  1 if a member ceases to be a public school employee for any reason, except while on official leave from service with the reporting unit, the person shall cease to be a member. The person's credited contributory membership service and credited prior service, and the noncontributory membership service credited during periods when the member contributed to the member investment plan, shall be forfeited and no longer in effect if the person withdraws the accumulated contributions from the retirement system. If the person returns to reporting unit service, the person shall again become a member. If accumulated contributions were withdrawn and the person returns for a period of not less than 1 year of credited service, the person may pay into the retirement system, before the effective date of the person's retirement, the amount withdrawn, together with simple interest on the amount withdrawn from the reserve for employee contributions and compound interest on the amount withdrawn from the reserve for member investment plan computed in each case from the date of withdrawal to the semiannual anniversary of the date of withdrawal following the date of repayment. Upon payment in full, the member shall be allowed credit for the service upon which the refund was based, which shall reinstate the previously forfeited service. However, a member who previously withdrew the contributions and who separated from reporting unit service for 60 consecutive calendar months shall not be allowed credit for the service upon which the refund was based until the member returns to service for 2 or more years of credited service and returns the accumulated contributions previously withdrawn, together with simple interest on the amount withdrawn from the reserve for employee contributions and compound interest on the amount withdrawn from the reserve for member investment plan computed in each case from the date of withdrawal to the semiannual anniversary of the date of withdrawal following the date of repayment.

(2) Upon a member's retirement or death, the member shall cease to be a member.