Mich. Comp. Laws § 600.226

Sec. 226. (1) The supreme court may authorize any retired judge from any court to perform judicial duties in any court in the state. The authorization may be for a period or periods as the supreme court shall designate with the consent of the retired judge. (2) Any retired judge assigned to any period of active judicial service pursuant to section 23 of article VI of the state constitution of 1963 and pursuant to the laws of the state relating to judicial service shall be compensated as follows: (a) The judge shall receive a salary payable at the same times and from the same sources as provided for the judicial office in which the judge is authorized to perform judicial duties. (b) The performance of the authorized judicial duties shall be without prejudice to all other rights of the judge under the retirement systems. (c) The salary for each day in which the judge serves as authorized shall be the greater of the following: (i) One hundred dollars per diem for each day or part of a day spent in the discharge of his or her duties. (ii) The difference between 1/250th of the annual salary paid for the judicial office during the time the retired judge serves in the office and 1/250th of the state retirement allowance paid to the retired judge during the time the retired judge serves in the office. (d) Necessary expenses incidental to the performance of duties required by the assignment, including travel, meals, and lodging, shall be paid by the state in accordance with the established provisions and procedures for state officials and upon the approval of the court administrator. (3) This section does not apply to the performance of judicial duties by a senior judge under sections 557, 557a, and 557b.