Mich. Comp. Laws § 38.1622: Payment date of retirement allowance; payment upon cessation of retirement allowance.

Sec. 22.

Each retirement allowance payable under this act shall date from the first of the month following the month in which the applicant satisfies the age and service or other requirements for receiving the retirement allowance and terminates state service. A full month's retirement allowance shall be payable for the month in which a retirement allowance ceases.