Mich. Comp. Laws § 38.1335

Sec. 35. The reserve for retired benefit payments is the account from which all retirement allowances and refunds pursuant to section 85(6) shall be paid. After receipt of each annual actuarial valuation as provided in section 41, the balance in the reserve for retired benefit payments shall be brought into balance with the actuarial present value of retirement allowances to be paid after the end of the fiscal year to retirants and retirement allowance beneficiaries in receipt of retirement allowances at the end of the fiscal year, by a transfer between the reserve for employer contributions and the reserve for retired benefit payments.