Mich. Comp. Laws § 37.232: Person with control over public accommodation or public service; prohibited conduct.

Sec. 2.

Unless expressly permitted by a state or federal statute or a regulation promulgated under a state or federal statute, a person with control over a place of public accommodation or public service shall not do any of the following:

(a) Deny the full and equal enjoyment of the goods, services, facilities, privileges, advantages, or accommodations of a place of public accommodation or public service to an individual because the individual is breastfeeding a child or is expressing human milk.

(b) Print, circulate, post, mail, or otherwise cause to be published a statement, advertisement, notice, or sign that indicates any of the following:

( i ) That the full and equal enjoyment of the goods, services, facilities, privileges, advantages, or accommodations of a place of public accommodation or public service will be refused, withheld from, or denied an individual because the individual is breastfeeding a child or is expressing human milk.

( ii ) That an individual's patronage of or presence at a place of public accommodation is objectionable, unwelcome, unacceptable, or undesirable because the individual is breastfeeding a child or is expressing human milk.