Michigan Compiled Laws, Chapter 500. Insurance Code of 1956 § 500.3158

Sec. 3158. (1) An employer, when a request is made by a personal protection insurer against whom a claim has been made, shall furnish forthwith, in a form approved by the commissioner of insurance, a sworn statement of the earnings since the time of the accidental bodily injury and for a reasonable period before the injury, of the person upon whose injury the claim is based.

(2) A physician, hospital, clinic or other medical institution providing, before or after an accidental bodily injury upon which a claim for personal protection insurance benefits is based, any product, service or accommodation in relation to that or any other injury, or in relation to a condition claimed to be connected with that or any other injury, if requested to do so by the insurer against whom the claim has been made, (a) shall furnish forthwith a written report of the history, condition, treatment and dates and costs of treatment of the injured person and (b) shall produce forthwith and permit inspection and copying of its records regarding the history, condition, treatment and dates and costs of treatment.