Mich. Comp. Laws § 38.2106

Sec. 106. (1) "Interest" means the rate or rates of interest per annum, compounded annually, as determined by the retirement board. (2) "Internal revenue code" means the United States internal revenue code of 1986. (3) "Judge" means a duly elected or appointed justice of the supreme court, judge of the court of appeals, judge of the circuit court, judge of the district court, judge of the probate court, or judge of the recorder's court of the city of Detroit. (4) "Medical adviser" means the medical adviser of the retirement system as provided in section 205. (5) "Member" means a judge or state official who is included in the membership of the retirement system as provided in section 401. (6) "Membership service" means service performed as a member under this act or under the former judges retirement system or former probate judges retirement system.