Voters in Washington state have approved Initiative 638, a ballot measure that bars transgender girls from competing on girls' K-12 school sports teams, Axios and The Guardian reported. The measure requires students seeking to play on female teams to submit a statement from a doctor verifying their sex, based on genetic makeup, reproductive anatomy or naturally produced testosterone levels.
The measure also allows penalties for organizations that violate the law. Students would not be punished unless they "knowingly violated the rules" or gained a significant competitive advantage or materially disadvantaged another student. The Washington Interscholastic Athletic Association said the law would take effect on Dec. 3, 2026, and that it would update its handbook to comply.

The association has reported knowing of only about 10 transgender athletes participating statewide each year. Before the election, more than 100 medical providers denounced the measure, saying it would interfere with the patient-physician relationship. The ACLU of Washington said it was "exploring all potential next steps to uphold the rights of transgender girls and their access to school sports."
Washington was one of four states, along with Arizona, Colorado and Nebraska, where restrictions on transgender athletes were approved or on track to pass on Tuesday, even as Democrats won sweeping victories elsewhere. Arizona's measure drew about 59% support, while Colorado's Proposition 134 was passing with 52%. Nebraska voters approved a constitutional amendment barring students of the male sex from girls' and women's teams.
According to Ballotpedia, 29 states have laws, regulations or interscholastic rules limiting participation on female school sports teams to students of the female sex.