Mich. Comp. Laws § 445.921

Sec. 21. (1) The commissioner of insurance may investigate, in the manner set forth in section 7, a person subject to Act No. 218 of the Public Acts of 1956, as amended, being sections 500.100 to 500.8302 of the Michigan Compiled Laws, who the commissioner believes has engaged, is engaging, or is about to engage in a method, act, or practice which is unlawful under this act. (2) When the commissioner requires the use of the subpoena power provided in this act, an application shall be made to the attorney general, who shall proceed to procure a subpoena on behalf of the commissioner in accordance with section 7. (3) Upon conclusion of an investigation, the commissioner shall provide a full report to the attorney general.