Mich. Comp. Laws § 691.1347

Sec. 17. (1) Subject to sections 18 and 19, a collaborative law communication is privileged under subsection (2), is not subject to discovery, and is not admissible in evidence. (2) In a proceeding, the following privileges apply: (a) A party may refuse to disclose, and may prevent any other person from disclosing, a collaborative law communication. (b) A nonparty participant may refuse to disclose, and may prevent any other person from disclosing, a collaborative law communication of the nonparty participant. (3) Evidence or information that is otherwise admissible or subject to discovery does not become inadmissible or protected from discovery solely because of its disclosure or use in a collaborative law process.