Marrying your cousin in Michigan is only possible if the wedding happens somewhere else. Michigan law voids any first cousin marriage performed inside the state, but it recognizes a first cousin marriage that was legally performed in another state or country. That single distinction, between where you marry and where you live afterward, controls almost every practical question on this topic.
The Michigan Ban on First Cousin Marriage
Two statutes set out the prohibition. MCL 551.3 bars a man from marrying his “cousin of the first degree,” along with parents, siblings, grandparents, and certain in-laws.1Michigan Legislature. Michigan Code 551.3 – Incapacity; Persons Man Prohibited From Marrying MCL 551.4 imposes the same restriction on women.2Michigan Legislature. Michigan Code Chapter 551 – Marriage The ban reaches only first cousins. Second cousins, third cousins, and more distant relatives can marry in Michigan without any restriction based on the relationship.
A separate statute, MCL 552.1, spells out the consequence. A marriage prohibited because of the blood relationship between the parties is “absolutely void” when solemnized within Michigan.3Michigan Legislature. Michigan Code Chapter 552 – Divorce Void means no legal effect from the moment the ceremony happens. The law treats the marriage as though it never occurred. A county clerk who spots the relationship on a marriage license application will simply refuse to issue the license.
Marrying in Another State and Living in Michigan
Michigan follows the place-of-celebration rule. A marriage that was valid where it was performed is valid in Michigan, even if it could not have been performed here. The Michigan Court of Appeals confirmed this in Toth v. Toth (1973), holding that Michigan’s prohibition applies only to marriages solemnized within the state. The Board of Immigration Appeals reached the same conclusion, noting that “a marriage which is valid where contracted is recognized as valid in the state of Michigan despite the fact that it would be invalid if contracted in Michigan.” A 1939 Michigan Attorney General opinion went further, stating that first cousins may leave the state specifically to marry in a jurisdiction that allows it and have that marriage recognized on their return.4U.S. Department of Justice. Matter of Balodis, Interim Decision 2805
The U.S. State Department’s Foreign Affairs Manual echoes the same rule. It notes that while first cousin marriages performed in Michigan are void, Michigan courts have recognized a first cousin marriage performed abroad as valid within the state.5U.S. Department of State. 9 FAM 102.8 – Family-Based Relationships
So if you marry a first cousin in California, New York, or a country where the union is legal, Michigan treats that marriage as valid. You have the same inheritance rights, property protections, and parental rights as any other married couple in the state.
What “Void” Means If a Ceremony Happens in Michigan Anyway
Because a void marriage is legally nonexistent, in theory you can walk away without filing anything. Unlike a voidable marriage, which needs a court order to undo, a void marriage never had legal standing. In practice, a formal annulment is the safer route. Without a court judgment on the record, you can run into complications later when applying for a new marriage license, dividing jointly held property, or resolving disputes over shared finances.
Children are protected regardless. MCL 552.1 states that children of a marriage voided for consanguinity are legitimate.3Michigan Legislature. Michigan Code Chapter 552 – Divorce Custody, child support, and inheritance rights are unaffected by the parents’ marriage being declared void. Courts handle those questions the same way they would for any other family.
No Criminal Penalties in Michigan
Michigan does not treat a first cousin marriage as a crime. The consequence is civil: the marriage is void. Some other states classify first cousin marriage as a criminal offense, but Michigan is not one of them. No one faces arrest, fines, or a criminal record for attempting to marry a first cousin here.
Federal Benefits When Your Marriage Was Valid Elsewhere
Federal agencies each apply their own test for a valid marriage, and the details matter when a union is void in one state but legal in another.
Family and Medical Leave
The FMLA defines “spouse” by the law of the state where the marriage was celebrated, not where the couple currently lives.6U.S. Department of Labor. Fact Sheet 28L – Leave Under the FMLA When You and Your Spouse Work for the Same Employer If your first cousin marriage was validly performed in another state, your employer should recognize it for FMLA purposes no matter where you now live.
Social Security
Social Security benefits generally depend on whether state law where the insured person lived recognizes the marriage. Because Michigan recognizes valid out-of-state cousin marriages, a surviving spouse in that situation should qualify for survivor benefits. Even where a marriage is technically void, Social Security has a “deemed valid marriage” provision: if you went through a marriage ceremony in good faith, believing it was legal, and you were living with the insured person, you may still qualify for spousal or survivor benefits.7Social Security Administration. 20 CFR 404.346 – Your Relationship Based Upon a Deemed Valid Marriage
Immigration
For marriage-based immigration petitions, USCIS looks at whether the marriage is valid in the jurisdiction where the couple lives or intends to live. If the couple resides in Michigan, the analysis returns to the same question: was the marriage performed somewhere it was legal? If so, Michigan recognizes it, and the immigration petition can proceed. The State Department’s Foreign Affairs Manual specifically addresses this scenario and cites the Michigan court ruling that upheld a first cousin marriage performed abroad.5U.S. Department of State. 9 FAM 102.8 – Family-Based Relationships
Is the Law Likely to Change?
No. Some advocates propose a conditional model similar to Illinois, where first cousin marriage is permitted when both parties are over 50 or one is medically unable to have children. Others suggest requiring genetic counseling in place of a blanket prohibition. Any change would require the Michigan Legislature to amend MCL 551.3 and 551.4, and there is no active bill or organized legislative push to do so as of 2026. For the foreseeable future, the rule is what it is: marry outside Michigan if you want the marriage to hold up, and Michigan will recognize it when you come home.