Mich. Comp. Laws § 123.621

Sec. 1. Any 2 or more cities, villages or townships, or any combination thereof, may contract jointly for employing an independent appraisal firm to make township, village and city appraisals or to assist the supervisors and assessing officials as directed by the contracting governing boards and councils. Expenses shall be paid from the general funds of the contracting governing bodies pursuant to their contractual agreement.