- Connecticut instituted a ban on first cousins marrying, effective October 1.
- Previously-made marriages between first cousins remain valid in Connecticut
- Some states put restrictions on first-cousin marriage, including requiring genetic counseling.
Connecticut’s ban on marriage between first cousins — the children of siblings — takes effect Oct. 1. The law, signed on June 23, makes it one of many states that totally ban such unions.
The law doesn’t restrict or penalize first-cousin couples who wed before the ban becomes law. Those marriages are still valid. The state had already said marriage between other close relatives, such as grandparents and their grandchildren is illegal.
Several states restrict such marriages, largely because the close familial relationship raises the potential to have children with serious birth defects.
A lot of states do allow first cousins to marry, though some place restrictions, and some are debating changes.
As of early 2025 — law changes can be a moving target — first-cousin marriages are legal in Alabama, Alaska, California, Colorado, Florida, Georgia, Hawaii, Maryland, Massachusetts, New Jersey, New Mexico, New York, North Carolina (double cousins may not marry), Rhode Island (as long as they are past childbearing age or are unable to have children), South Carolina, Vermont and Virginia. The District of Columbia allows it, as well.
South Dakota not only bars first cousins from marrying, but also says that sexual relations and cohabiting are illegal.
Some states allow first-cousin weddings as long as the couple has genetic counseling. That’s the case in Maine.
Arizona allows such marriages if both parties are over 65 or one is infertile, while Illinois has similar restrictions but sets the age of both at 50. Indiana allows such marriages after both parties turn 65. So does Utah, but it drops the age to over 55 if the couple can’t produce offspring. Wisconsin says the woman has to be 55 or older or one of the spouses needs to be infertile. But two male first cousins can marry.
On the other hand, Delaware declares first-cousin marriages “void.” The state legislature debated honoring first-cousin marriages that took place in other states, then decided not to do so. The bill failed in the House.
Tennessee has changed its mind before and allowed it, but now bans marriage among first cousins.
Some states criminalize marriage between first cousins, but most don’t.