Secretary of State Jena Griswold certified Colorado’s 2026 general election ballot on 4 September 2026, with 14 statewide measures. Two are on our sex-based-rights beat. Election day is 3 November, and ballots are already in the mail. The Secretary lists 26 October as the last suggested day to return ballots by mail.

Proposition 134: “Male and Female Participation in School Sports” (Initiative #109)

  • Interscholastic and intramural teams sponsored by a school or athletic association must be designated male, female, or coeducational/mixed “based on biological sex”. The definition of “school” covers public, charter, private and religious K–12 schools and postsecondary institutions.
  • Female teams “shall not be open to a male student”. Male teams are closed to females unless no female team exists.
  • Government bodies and athletic associations may not open investigations or take adverse action against a school for keeping a separate female team.
  • Enforcement is by the Commissioner of Education. People with differences of sex development keep their federal legal protections.

Proposition 135: “Prohibit Certain Surgeries for Minors” (Initiative #110)

  • No health-care professional may knowingly “perform, prescribe, administer, or provide any surgery to a minor for the purpose of altering biological sex characteristics”.
  • No state or federal funds, Medicaid reimbursement or insurance coverage may pay for it.
  • Exempts treatment of medically verifiable disorders of sex development, and male circumcision. The measure covers surgery only, not puberty blockers or hormones.
A health-care professional or other person shall not knowingly perform, prescribe, administer, or provide any surgery to a minor for the purpose of altering biological sex characteristics. — Initiative #110, final text

The Secretary of State lists both as proposed statutory changes, not constitutional amendments. Both take effect 1 January 2027 if approved.

Citizen impact: Colorado parents, athletes and schools: Prop 134 would decide who may play on girls’ and women’s teams statewide, including at private schools and colleges. Prop 135 would bar surgery for under-18s in this category and its insurance coverage. If you have a mail ballot, 26 October is the last suggested day to mail it back. After that, use a drop box or voting centre.

What this piece refuses

We do not report polls or predict outcomes. We describe what the measure texts say, not what either campaign claims they will do. We do not say Prop 135 covers drugs or hormones, because it does not. We also make no claim about how many surgeries on minors happen in Colorado. The measure gives no figure, and we have not verified one.

Bottom line

On 3 November Coloradans decide two statutes: sex-based school sports teams (Prop 134) and a ban on sex-trait surgery for minors, with its public and insurance funding (Prop 135). Both would take effect 1 January 2027.