Michigan Compiled Laws, Chapter 600. Revised Judicature Act of 1961 § 600.2912f

Sec. 2912f. (1) A person who has given notice under section 2912b  1 or who has commenced an action alleging medical malpractice waives for purposes of that claim or action the privilege created by section 2157  2 and any other similar privilege created by law with respect to a person or entity who was involved in the acts, transactions, events, or occurrences that are the basis for the claim or action or who provided care or treatment to the claimant or plaintiff in the claim or action for that condition or a condition related to the claim or action either before or after those acts, transactions, events, or occurrences, whether or not the person is a party to the claim or action.

(2) Pursuant to subsection (1), a person or entity who has received notice under section 2912b or who has been named as a defendant in an action alleging medical malpractice or that person's or entity's attorney or authorized representative may communicate with a person specified in section 5838a  3 in order to obtain all information relevant to the subject matter of the claim or action and to prepare the person's or entity's defense to the claim or action.

(3) A person who discloses information under subsection (2) to a person or entity who has received notice under section 2912b or to a person or entity who has been named as a defendant in an action alleging medical malpractice or to the person's or entity's attorney or authorized representative does not violate section 2157 or any other similar duty or obligation created by law and owed to the claimant or plaintiff.