Michigan Compiled Laws, Chapter 722. Children § 722.1003

Sec. 3. (1) If a child is born out of wedlock, a man is considered to be the natural father of that child if the man joins with the mother of the child and acknowledges that child as his child by completing a form that is an acknowledgment of parentage.

(2) If a child born out of wedlock is conceived by assisted reproduction as defined in the assisted reproduction and surrogacy parentage act,  1 an individual is considered to be the natural parent of that child if the individual joins with the individual who gave birth to the child and acknowledges that child as their child by completing a form that is an acknowledgment of parentage.

(3) If a child is born to a married individual who gave birth to a child conceived by assisted reproduction as defined in the assisted reproduction and surrogacy parentage act, their spouse is considered to be an acknowledged parent by completing a form that is an acknowledgment of parentage.

(4) An acknowledgment of parentage form is valid and effective and establishes the parentage of a child if signed by individuals eligible to acknowledge parentage as set forth in subsections (1), (2), and (3) and those signatures are each notarized by a notary public authorized by the state in which the acknowledgment is signed or witnessed by 1 disinterested, legally competent adult. The witness must be an employee of 1 of the following: a hospital, publicly funded or licensed health clinic, pediatric office, friend of the court, prosecuting attorney, court, department of health and human services, county health agency, county records department, head start program, local social services provider, county jail, or state prison. The witness must sign and date the acknowledgment of parentage form and provide his or her printed name, address, and place of employment. An acknowledgment may be signed any time during the child's lifetime.

(5) The birth parent and the acknowledged parent must be provided a copy of the completed acknowledgment at the time of signing.