Mich. Comp. Laws § 600.2925d: Effect of release, covenant not to sue, or covenant not to enforce judgment.

Sec. 2925d.

If a release or a covenant not to sue or not to enforce judgment is given in good faith to 1 of 2 or more persons for the same injury or the same wrongful death, both of the following apply:

The release or covenant does not discharge 1 or more of the other persons from liability for the injury or wrongful death unless its terms so provide.

The release or covenant discharges the person to whom it is given from all liability for contribution to any other person for the injury or wrongful death.