No, it is not illegal to marry your second cousin anywhere in the United States. Every state allows it, no state has ever banned it, and the marriage receives the same legal treatment as a marriage between two unrelated people. There are no special disclosures, no genetic counseling requirements, and no age restrictions beyond the ones that apply to everyone.
What a Second Cousin Actually Is
A second cousin is someone who shares your great-grandparents but not your grandparents. Your respective grandparents were siblings, which made your parents first cousins, which makes the two of you second cousins. That is one full generation further removed than a first cousin.
On the consanguinity chart courts use to measure family closeness, second cousins sit at the sixth degree of relatedness. Siblings are at the second degree. First cousins are at the fourth. That gap matters, because every state draws its marriage prohibition line well before the sixth degree.
Where State Marriage Laws Draw the Line
State marriage laws prohibit unions between relatives using those same degrees of consanguinity. Every state bans marriage between a parent and child, between siblings, and between a person and their grandparent, grandchild, aunt, uncle, niece, or nephew. Those cover the first through third degrees, and the prohibitions are universal.
States start disagreeing at the fourth degree, which is first cousins. Roughly half ban first cousin marriage outright. The other half permit it, either without conditions or with specific restrictions. A handful of states extend the ban one step further to first cousins once removed. None go beyond that. The genetic and social arguments behind consanguinity laws lose their force at greater distances, and no state legislature has treated second cousin marriage as something worth regulating.
Don’t Confuse This With First Cousin Rules
Searchers often arrive at the second cousin question because they have heard that cousin marriage is restricted somewhere. The restrictions they are thinking of apply to first cousins, and the picture there is genuinely mixed.
About 17 states and the District of Columbia allow first cousin marriage without conditions, including California, New York, Colorado, Florida, Georgia, and Virginia. Another group permits it only under specific circumstances. Arizona, Illinois, Indiana, and Utah allow first cousins to marry once both parties are above a specified age, typically 50 or 65, on the theory that children are unlikely at that point. Wisconsin allows the marriage if the woman is over 55 or one partner is medically certified as unable to reproduce. Maine permits it after both parties complete genetic counseling. The remaining states prohibit first cousin marriage entirely, and some refuse to recognize first cousin marriages performed elsewhere.
None of this applies to second cousins. Even in the strictest first cousin states, a second cousin marriage raises no legal issue.
The Genetic Risk Question
The reason consanguinity laws exist in the first place is genetic. Closely related parents are more likely to carry the same recessive gene variants, which raises the chance a child inherits two copies of a harmful mutation. That risk drops sharply with each degree of separation.
Second cousins share about 3.4% of their DNA on average, ranging from roughly 1% to 6%. First cousins share about 14%. The baseline risk of a birth defect for any couple in the general population sits around 2 to 3%. For second cousins, the risk rises to approximately 3.5%, a difference most genetic counselors consider clinically insignificant.
A 2025 study indexed in the National Center for Biotechnology Information database found that children of second cousins carried about twice as many rare harmful homozygous gene variants as children of unrelated parents. The absolute numbers remain low, and the finding is consistent with the modest real-world risk increase above. The elevated variant count reflects a statistical pattern rather than a likely health outcome for any individual child.
Getting the Marriage License
Applying for a marriage license as second cousins is no different from applying as any other couple. You go to the county clerk or probate judge in the jurisdiction where you plan to marry, complete the application with your names, ages, and residences, and swear or affirm that you are legally entitled to marry. Some states ask applicants to disclose whether they are related. Answering truthfully that you are second cousins will not stop the license from being issued.
Fees, waiting periods, and premarital counseling discounts vary by jurisdiction, but none of these procedural details change based on your family connection.
Moving to Another State
Because every state permits second cousin marriage, interstate recognition is a non-issue. The general American rule is that a marriage valid where it was performed is valid everywhere, sometimes called the place-of-celebration rule. States occasionally refuse to recognize an out-of-state marriage that deeply offends their own public policy, and that narrow doctrine has come up with first cousin marriages. It has no practical application to second cousins, because no state has a public policy against the marriage to begin with.
Federal Benefits and Immigration
Federal agencies follow the same place-of-celebration rule. If your marriage was legal where it was performed, the federal government treats it as valid for taxes, Social Security survivor benefits, and other programs. Second cousin marriage is legal everywhere, so no federal complication arises.
USCIS recognizes a marriage as valid for immigration purposes if it was legally performed in the place of celebration, is consistent with U.S. public policy, and was entered into in good faith. When close relatives are involved, USCIS also checks whether the marriage lines up with the laws of the state where the couple lives or plans to live. That scrutiny has come up in first cousin petitions. For second cousins it is irrelevant, since every state treats these marriages the same as any other.
The State Department’s Foreign Affairs Manual gives visa adjudicators the same instruction: the law of the place of celebration controls, except where the marriage would be void under the public policy of the state of intended immigration. Second cousin marriages face no such obstacle.