Michigan Compiled Laws, Chapter 330. Mental Health Code § 330.1629

Sec. 629. (1) A guardian, temporary guardian, plenary, partial, or standby guardian shall not be liable for civil damages by reason of authorizing routine or emergency medical treatment or surgery or extraordinary procedures when previously ordered by the court for his or her ward if the guardian acted after medical consultation with the ward's physician, acted in good faith, was not negligent, and acted within the limits established for the guardian by the court.

(2) A guardian, temporary guardian, plenary, partial, or standby guardian who has been authorized by the court to give medical consent, shall not be liable by reason of his or her authorization for injury to the ward resulting from the negligence or other acts of a third person.

(3) Routine medical services do not include extraordinary procedures. Extraordinary procedures includes, but is not limited to, sterilization, including vasectomy, abortion, organ transplants from the ward to another person, and experimental treatment.