Mich. Comp. Laws § 500.3183

Sec. 3183. An automobile insurer may offer a managed care option that provides for allowable expenses consisting of all reasonable charges incurred for reasonably necessary products, services, and accommodations for an injured person's care, recovery, or rehabilitation. This managed care option is subject to all of the following: (a) It must be uniformly offered in all areas where the managed care option is available. (b) It must provide a discount that reflects reasonably anticipated reductions in losses or expenses or both. (c) It must not apply to emergency care. Emergency care includes, but is not limited to, all care necessary to the point where no material deterioration of a condition is likely, within reasonable medical probability, to result from or occur during transfer of the patient.