Key Highlights
- Connecticut becomes the 26th U.S. state to outlaw first-cousin marriages.
- The legislation was passed with rare unanimous agreement in the Democrat-majority state.
- Lawmakers highlighted increased risks of birth defects from cousin unions.
Starting October 1, 2025, the Connecticut cousin marriage ban will take effect, making the state the 26th in the U.S. to outlaw such unions. The bill, which passed earlier this year, won rare bipartisan support in a legislature typically dominated by Democrats.
The legislation is direct in its language: “No person may knowingly marry such person’s first cousin.” Until now, Connecticut’s marriage laws prohibited unions between parents, children, and step-relatives but did not explicitly restrict first-cousin marriages.
Inspiration from Other States
Republican State Rep. Devin Carney of Old Saybrook spearheaded the initiative after discovering that Tennessee had recently passed a similar ban.
“I was told it’s not banned in Connecticut, so I started looking into it, and over 30 states do ban it, and Connecticut is not one of them,” Carney explained in an interview with the Connecticut Post.
His proposal sparked renewed debate over first cousin marriage laws, with lawmakers acknowledging that Connecticut stood out in New England for permitting such unions.
Public Health and Legal Considerations
Democratic State Rep. Steve Stafstrom, a co-sponsor of the bill, emphasized public health risks as a key driver. Studies indicate that children born to first cousins face higher risks of genetic disorders, heart conditions, premature birth, and infant mortality.
The new law & policy do not invalidate existing marriages. Instead, they apply only to future unions, aiming to prevent potential health risks and close what legislators described as a long-standing loophole in Connecticut’s marriage laws by state framework.
Connecticut Joins Majority of States
With this step, Connecticut becomes the 26th state to impose a complete prohibition on first-cousin marriages. Other states, including Maine and Arizona, allow such unions under certain conditions, such as infertility or genetic counseling. In contrast, Connecticut will now join New Hampshire as the only New England state with outright bans.
Lawmakers argue that the Connecticut cousin marriage ban brings the state in line with national trends while also protecting families from preventable health issues.
Broader Legal Context
Across the United States, U.S. states banning cousin marriages form a patchwork of regulations. While 26 states now impose full bans, others permit first cousins to marry under limited circumstances. Advocates of Connecticut’s new law say the change reflects both evolving public health standards and efforts to modernize outdated family codes.
By enacting this reform, Connecticut aims to ensure that its marriage legal laws by state align more closely with national norms while prioritizing the health and well-being of future generations.