Connecticut to ban first-cousin marriages, joining majority of states

Connecticut lawmakers approved a bill to ban marriages between first cousins, with the measure taking effect Oct. 1 in a rare display of cross-party agreement in the Democratic-led state.

Under the legislation, no person may knowingly marry such person’s first cousin, the text of the bill states. The ban fills a gap in state law that previously prohibited marriages between immediate family members but did not address first cousins. Connecticut will ban first‑cousin marriages effective Oct. 1, part of a broader review of family-law provisions that some lawmakers said was long overdue.

State Rep. Devin Carney, a Republican who represents Old Saybrook, pushed the measure after learning that many states ban such unions. He told the Connecticut Post that he pursued the change because he found Connecticut “was not one of them” when he learned Tennessee had recently banned first‑cousin marriages and that more than 30 states had total bans. “Somebody actually sent me an article about it. Tennessee recently banned it. They passed a law to ban it. 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 said. His effort, he said, was to bring the state into line with broader national trends rather than in response to a local controversy.

State Rep. Steve Stafstrom, a Democrat who co‑sponsored the bill, argued that the science supports a cautious approach to cousin marriage. He cited concerns that procreation between first cousins is associated with higher risks of birth defects and other health issues. “Science shows that procreation between first cousins increases the chances of birth defects,” Stafstrom said, noting that the bill aims to protect public health without punishing marriages that occurred when such unions were lawful. The National Library of Medicine and other medical sources are commonly cited in discussions of these risks.

Connecticut will be the 26th state to ban first‑cousin marriages outright. Before passage, at least 25 states had total bans, while many others place restrictions on cousin unions rather than prohibiting them entirely. In New England, Connecticut and New Hampshire are the only states with strict prohibitions; Maine permits cousin marriages under certain circumstances, including genetic counseling, according to state law. Elsewhere, states such as Arizona, Illinois and Indiana have allowed cousin marriages under specific conditions—such as when both parties are near-geriatric or are infertile.

As Stafstrom noted, historical patterns show that cousin marriage was legal in all states prior to the Civil War, and today the practice remains restricted in many places. Proponents say the changes reflect evolving public health considerations and attempts to balance individual rights with broader social and medical concerns. Connecticut’s action follows similar moves in other states that have chosen to address the issue head‑on through statutory bans rather than leaving the practice in a legal gray area.

Minnesota, for example, limits first‑cousin marriages to contexts aligned with established customs of aboriginal cultures, while North Carolina permits only double first cousins—children of two sisters who married two brothers—under state law. The landscape remains complex, with roughly half of the states lacking a blanket ban altogether. Beyond New England, policy varies widely, underscoring how states continue to navigate family-law questions with differing approaches.

The policy shift in Connecticut arrives at a time when a patchwork of state rules on intimate family unions continues to evolve. While the Oct. 1 effective date is fast approaching, the measure’s passage is widely framed by lawmakers as a public-health precaution that also aligns Connecticut with many peers in limiting genetic risks associated with consanguineous unions. The state’s enactment adds a legal certainty for couples and families, while signaling ongoing debates over how to regulate marriage within families without intruding on personal history and circumstance.

The broader political conversation around the legislation emphasizes bipartisan interest in safeguarding future generations, even as some neighbors and peers maintain more permissive rules. Connecticut’s experience could influence nearby states considering similar reforms in the coming legislative sessions, as lawmakers weigh medical data, cultural history, and constitutional considerations in shaping modern family law.