Mich. Comp. Laws § 460.38: Notice of rate change or other changes; time period; publication.

Sec. 8.

(1) A cooperative electric utility that is member-regulated shall publish notice of any rate change or any change in billing practices and service rules or terms and conditions of service at least 30 days prior to the effective date of the change.

(2) The notice under this section shall be sent by first-class mail to all members or may be published in a periodical issued by an association of cooperative electric utilities and mailed to each member of record of the cooperative electric utility.