Michigan Compiled Laws, Chapter 550. General Insurance Laws § 550.825

Sec. 15. (1) A pharmacy benefit manager shall exercise good faith and fair dealing in the performance of its contractual duties to a health plan or network pharmacy. A provision in a contract that attempts to waive or limit the obligation under this subsection is void.

(2) A pharmacy benefit manager shall notify a health plan in writing of any activity, policy, or practice of the pharmacy benefit manager that directly or indirectly presents a conflict of interest with the duties imposed in this section.

(3) A pharmacy benefit manager shall not directly or indirectly, including indirectly through a pharmacy services administrative organization, charge or hold a pharmacist or pharmacy responsible for a fee related to a claim or reduce the amount of the claim at the time of the claim's adjudication or after the claim is adjudicated.

(4) This section does not apply to an audit under section 28  1 of a pharmacy's records if either of the following applies:

(5) Except for the recoupment of money under an audit conducted under section 28, a pharmacy benefit manager shall not recoup money from a pharmacist or pharmacy in connection with a claim for which the pharmacist or pharmacy has been paid unless the recoupment is required by law.