Marrying your first cousin became illegal in Connecticut on October 1, 2025, under a new state law prohibiting such unions. Previously legal, the change aligns Connecticut with most U.S. states restricting close-kin marriages for genetic and social reasons.
Historical Context
Before October 1, 2025, Connecticut was one of about 18 states allowing first-cousin marriages without restrictions, alongside places like New Jersey and New York. State law (Conn. Gen. Stat. § 46b-21) already voided marriages between parents, grandparents, siblings, aunts/uncles, nieces/nephews, stepparents, or stepchildren.
Public Act 25-72 (HB 6918) expanded prohibitions to first cousins, effective prospectively—pre-2025 cousin marriages remain valid.
Current Law Details
No person may knowingly marry their first cousin on or after October 1, 2025. Eligibility requires being 18+, not in another marriage or equivalent relationship, not under conservatorship without consent, and free from prohibited kin ties.
Violations don’t automatically void the marriage or trigger criminal penalties, but officials won’t issue licenses. Couples must wed elsewhere if allowed, though recognition varies.
Nationwide Comparison
About 32 states ban or heavily restrict first-cousin marriage; 18 permit it.
Genetic and Social Rationale
First-cousin offspring face 4-6% risk of birth defects, double unrelated couples’ 2-3%. Recessive genes increase issues like cystic fibrosis. Cultural stigma and inbreeding concerns drove the ban, mirroring Tennessee’s 2024 law.
Supporters cited child welfare; opponents noted low incidence and adult autonomy.
Enforcement and Exceptions
Town clerks verify relations via affidavits or documents before licensing. No retroactive invalidation protects existing families. Out-of-state cousin marriages may be recognized if valid where performed, per comity principles.
Second cousins or remoter kin face no bans.
Practical Implications
- Licensing: Affirm no cousin relation post-2025.
- Travel Weddings: Legal in permissive states, but Connecticut residency complicates residency-based benefits.
- Divorce/Inheritance: Pre-ban marriages unaffected.
Consult family records or genealogists for ties. Legal challenges unlikely given legislative intent.
Advice Moving Forward
Genetic counseling recommended regardless. For borderline cases, seek probate or family court clarification. The law prioritizes preventing future unions over punishing past ones.
SOURCES:
- https://www.deseret.com/family/2025/09/23/where-first-cousins-marry-connecticut-ban-which-states-legal/
- https://theamm.org/marriage-laws/connecticut
