Mich. Comp. Laws § 38.841

Sec. 1. As used in this act: (a) "Local unit of government" means a county, city, township, or other political subdivision of this state which offers its employees a retirement plan in which a judge may be a member. (b) "Judge" means a judge of the district court, the circuit court, or the recorder's court of the city of Detroit, who has converted a portion of his or her state salary standardization payment as an addition to his or her state base salary under section 14a or 14c of Act No. 198 of the Public Acts of 1951, as amended, being sections 38.814a and 38.814c of the Michigan Compiled Laws. For purposes of sections 2 and 6, "judge" also means a judge of the probate court.