Mich. Comp. Laws § 38.1014

Sec. 14. "Refund beneficiary" means the 1 or more persons named by a member, deferred vested member, or retirant in writing and filed in the office of the retirement system to receive any refund of a member, deferred vested member, or retirant's contributions upon his or her death if a survivor's retirement allowance is not payable under this act. In the absence of a valid beneficiary designation, refund payment shall be made to the executor or personal representative of the deceased for the benefit of the estate.