Mich. Comp. Laws § 333.27904

Sec. 4. (1) The information in the system is confidential and is exempt from disclosure under the freedom of information act, 1976 PA 442, MCL 15.231 to 15.246. Information in the system may be disclosed pursuant to subsection (2) or for purposes of enforcing this act; the Michigan medical marihuana act, 2008 IL 1, MCL 333.26421 to 333.26430; and the medical marihuana facilities licensing act. (2) A licensee may, in writing, authorize the department to disclose the licensee's information in the system described in section 3(2)(a) to (c) to a financial institution identified in the authorization. Upon receiving written authorization under this subsection, the department shall disclose the licensee's information described in section 3(2)(a) to (c) to a financial institution identified in the authorization.