Michigan Compiled Laws, Chapter 205. Taxation § 205.744

Sec. 44. (1) Except for petitions filed under chapter 6,  1 the tax tribunal may permit the intervention or impleading of any governmental unit which receives tax funds from the petitioner who is making the appeal.

(2) If a petition is filed under chapter 6, the tribunal may permit the intervention or impleading of a state or local governmental unit or officer thereof or of any person or other entity upon a showing of a material monetary interest in the decision of the tribunal which is not likely to be adequately presented by the parties to the proceeding.