Colorado voters approved sweeping bans on gender‑affirming care for minors and on mixed‑sex school sports, cementing the state’s new restrictions.
A lone voter casts his ballot at the South Branch Library during the presidential primary in Breckenridge, Colo., on March 5, 2024. Jason Connolly/AFP
Proposition 134 amends state statutes to require every school sports program—from elementary through college—to be designated “male‑only” or “female‑only” based on biological sex, unless the team is open to all sexes.
Schools must assign athletes to teams matching their sex and may not investigate or penalize institutions that offer female‑only programs.
Proposition 135 enacts a full ban on surgery for minors intended to alter biological sex characteristics and prohibits private insurance and Medicaid from covering such procedures.
The measure declares that children lack the maturity to make permanent, life‑altering medical decisions.
It warns that surgical interventions often cause serious, irreversible outcomes, including sterility.
The proposition notes that Colorado already bars minors from using controlled substances and argues the same safeguards should apply to irreversible gender‑related procedures.
The measures take effect on January 1, 2027.
Voters passed the measures after years of failed attempts to enact similar restrictions through Colorado’s Democratic‑controlled Legislature.
Just one year earlier, the Legislature approved a bill guaranteeing state‑regulated insurance coverage for “gender‑affirming health care.”
Measures in Other States
Voters in Washington approved a ban on male students—including those identifying as transgender—from competing in sports designated for female athletes.
Arizona voters passed Proposition 318, requiring students to use restrooms, locker rooms and other athletic facilities that correspond with their sex.
The law also forces schools and athletic associations to label teams as male, female or co‑ed and to bar males from female‑designated competitions.
In Missouri, a ballot amendment that would have prohibited gender‑transition surgeries and hormone treatments for minors was rejected.
Prior to the 2026 election, dozens of states—including Texas, Florida, Tennessee, Idaho and Arkansas—had already implemented policies restricting male athletes from female school sports.
Almost as many states have enacted bans on gender‑transition surgeries for minors, with Arkansas leading the way in 2021.
Stacy Robinson contributed to this report.
