Establishing Paternity in Michigan: A Guide for Unmarried Parents

Michigan law (the Paternity Act, MCL 722.711 et seq., and the Acknowledgment of Parentage Act, MCL 722.1001 et seq.) treats an unmarried biological father as a legal stranger to his child until paternity is formally acknowledged or adjudicated. Without that step, a father cannot petition for custody or parenting time, cannot make medical or educational decisions, and cannot be added to the birth certificate as the legal father.

For the child, the consequences are just as significant. A child without an established legal father cannot receive court-ordered child support, is not automatically eligible for the father's health insurance, and may lose access to Social Security survivor benefits, veterans' benefits, and inheritance rights if the father dies without a will.

For the mother, establishing paternity is the gateway to a support order and to sharing parenting responsibilities on the record — not by informal agreement.

The Affidavit of Parentage (often called an AOP) is a signed, notarized document in which both parents voluntarily agree that the man signing is the child's biological and legal father. Once signed by both parents and filed with the Michigan Department of Health and Human Services (MDHHS) Central Paternity Registry, it has the same legal effect as a court order of paternity.

The AOP can be signed at the hospital right after birth, or any time afterward at a local MDHHS office, Friend of the Court office, or in front of a notary. There is no filing fee. Once filed, the father's name is added to the birth certificate and he becomes the legal father for all purposes — custody, support, inheritance, and benefits.

Important limitation: signing an Affidavit of Parentage does not, by itself, give the father custody or parenting time. It only establishes legal fatherhood. To share custody or set a formal parenting-time schedule, one of the parents still has to file a custody action in Family Court.

The Affidavit of Parentage is only appropriate when both parents genuinely agree on paternity. If there is any doubt — the mother is unsure who the biological father is, the alleged father questions whether the child is his, or a different man is already the presumed father because the mother was married at conception or birth — the AOP should not be signed. Signing an AOP under those circumstances can lead to serious legal problems and can be difficult to undo.

In any of those situations, the correct next step is DNA testing under a court-admissible chain of custody, followed by a paternity action in Michigan Family Court.

When paternity is disputed, either parent — or the Michigan Department of Health and Human Services on behalf of a child receiving public assistance — can file a paternity action in the circuit court's Family Division in the county where the mother or child lives. The court can then order genetic testing of the mother, the child, and the alleged father.

Under MCL 722.716, a properly conducted DNA test showing a probability of paternity of 99% or greater creates a legal presumption that the tested man is the father. In practice, modern testing routinely produces probabilities of 99.99%+ when the tested man is the biological father, and definitive exclusions when he is not.

Once the results are back, the court enters an Order of Filiation. That order establishes legal paternity, sets initial child support, and opens the door to custody and parenting-time orders.

Michigan Family Courts and the Friend of the Court will not accept a home paternity kit from a pharmacy or online seller — even if the science behind the test is identical. What courts require is chain of custody: documented proof that the samples came from the named individuals and could not have been swapped, contaminated, or tampered with between collection and analysis.

A court-admissible test includes government-issued photo ID verification for every adult participant, a witnessed cheek-swab collection performed by a neutral third-party collector, tamper-evident packaging, direct shipment to an AABB-accredited laboratory, and a signed report referencing the case, the collector, and the chain-of-custody documentation.

NorthStar Lab Services coordinates every step of that process. Collections are performed in our Saginaw office or by statewide mobile appointment, and analysis is performed by our AABB-accredited partner laboratory. Results are typically available in 3–5 business days after the lab receives all samples.

Michigan law presumes that a child born during a marriage is the legal child of the husband, even if another man is the biological father. That presumption is powerful — it means the biological father cannot simply sign an Affidavit of Parentage. Instead, the parties usually need to proceed under the Revocation of Paternity Act (MCL 722.1431 et seq.), which requires a court filing and, almost always, court-ordered DNA testing to rebut the marital presumption.

If this is your situation, talk to a Michigan family-law attorney before testing. The timing of the filing and the type of order requested matter, and an attorney can make sure the DNA results are collected in a way the court will accept.

Once paternity is established — by AOP or by Order of Filiation — an unmarried father has the same legal standing as a married father. He can petition for legal custody (decision-making), physical custody (where the child lives), and parenting time. He is also legally responsible for child support, calculated under the Michigan Child Support Formula based on both parents' incomes and the parenting-time schedule.

Neither parent has an automatic advantage in a Michigan custody case. Courts decide custody and parenting time based on the twelve 'best interest of the child' factors listed in MCL 722.23 — including the emotional ties between parent and child, capacity to provide care, stability of the home environment, and the child's own reasonable preference when old enough.

If both parents agree on paternity and the mother was not married to another man at conception or birth, the fastest path is signing an Affidavit of Parentage — at the hospital, at a local MDHHS or Friend of the Court office, or in front of a notary.

If paternity is disputed, if the mother was married to another man, or if a court, attorney, or Friend of the Court has asked for DNA evidence, the right starting point is a court-admissible paternity test. NorthStar Lab Services can schedule a chain-of-custody collection in Saginaw or by mobile appointment anywhere in Michigan, coordinate testing with our AABB-accredited partner laboratory, and provide a signed report that Michigan Family Courts, the Friend of the Court, and Vital Records will accept.

This guide is general information about Michigan law, not legal advice. For advice about your specific situation — especially cases involving marriage, existing court orders, or disputed paternity — talk to a licensed Michigan family-law attorney.