Colorado voters will decide next month whether to ban people younger than 18 from receiving gender-affirming surgeries in the state, a question that has split medical groups, parents, and advocacy organizations ahead of the November 3 election. Proposition 135 needs only a simple majority to pass, since it would change state law rather than amend the state constitution.
The measure, as reported by The Denver Post, would prohibit surgeries that alter biological sex characteristics in minors when performed because of their feelings about gender or sex, and it would bar Medicaid and private insurance from covering such procedures. Gender-affirming surgeries are rare among people under 18, and Colorado hospitals do not currently offer them to minors, according to the same report. The measure does not define biological sex characteristics or surgery, but it exempts male circumcision and allows surgeries on atypically developing sexual organs or to correct a physical condition that develops in childhood.
A September 2026 analysis draft by the Colorado General Assembly noted that Proposition 135 does not explicitly list forbidden surgical procedures by name, but instead bases its prohibition on whether a procedure is performed as a treatment in response to a minor's perception of sex or gender. That phrasing has become central to the fight over what the measure would actually touch in doctors' offices across the state.
Doctors Warn the Ban's Wording Reaches Beyond Transgender Care
The Colorado Medical Society, the state's largest physician organization representing more than 6,000 doctors, voted on September 18 to formally oppose Proposition 135. The board warned that legislative interference in physician-led care could disrupt broader pediatric healthcare, not just treatment tied to gender identity, according to News From The States. That warning echoes the General Assembly's own finding that the measure's language targets physician rationale rather than naming specific procedures, which critics argue could create ambiguity for conditions unrelated to transgender care.
Opponents of the measure argue it could make it harder for cisgender youth to access healthcare for conditions affecting their chests or genitalia, per The Denver Post's reporting. Jack Teter, vice president of government affairs for Planned Parenthood of the Rocky Mountains, said the proposition transfers power from parents and medical providers to the government. Medical groups broadly believe chest surgery should remain an option for teens with severe gender dysphoria, while treatment for the condition also includes non-medical changes such as dressing differently, puberty blockers for preteens, and hormonal therapy for teenagers.
Supporters Say the Measure Protects Kids From Irreversible Choices
Patricia McKernan, a board member of Protect Kids Colorado, one of two registered issue committees supporting Proposition 135, said the measure protects children from decisions that could make it impossible for them to have children as adults. Supporters argue that minors cannot make fully informed choices about medical interventions and that gender-affirming surgeries carry risks of infertility, other complications, and regret, according to The Denver Post. Opponents counter that doctors and parents, not the state, are best placed to assess the medical care transgender teenagers need.
The state's official Blue Book voter guide estimates that additional costs to change regulations under the measure would be minimal, and that any Medicaid savings from no longer covering gender-affirming surgeries would also be minimal. Proposition 135 is part of a broader three-initiative slate placed on the ballot by Protect Kids Colorado, which also pairs it with Proposition 134 on transgender youth sports participation and Proposition 133 on child sex trafficking penalties, according to the Denver Gazette.
A National Test Case in a State Built as a Safe Haven
Proposition 135 marks the first citizen-initiated ballot measure seeking to restrict youth gender care in a Democratic-leaning state, while similar restrictions in more than 20 other states were enacted directly through state legislatures, according to MultiState. That framing matters in Colorado, which enacted Senate Bill 23-188 in April 2023, establishing statutory shield protections that prevent state agencies and courts from assisting out-of-state legal actions or civil subpoenas targeting legal reproductive and gender-affirming healthcare, per the Movement Advancement Project.
LGBTQ+ advocacy organization Rocky Mountain Equality formed the Hands Off Colorado coalition this year to campaign against Propositions 134 and 135, framing the measures as national political campaigns targeting vulnerable youth, according to Rocky Mountain Equality. The fight also follows a tense stretch in Colorado courts: in May, the Colorado Supreme Court ruled 5-2 in Boe v. Children's Hospital Colorado that the hospital violated state anti-discrimination law by suspending non-surgical gender care under federal pressure, while noting Children's Hospital has never performed gender-affirming surgeries on minors, the Colorado Sun reported.
Hospitals Caught Between State Mandates and Federal Pressure
In September, a Denver District Court judge ruled that Children's Hospital Colorado satisfied a court injunction by reinstating gender care into its operational scope, even though individual doctors at its TRUE Center independently declined to write new prescriptions amid federal legal concerns, Colorado Newsline reported. That same month, 9News reported that federal Health and Human Services Secretary Robert F. Kennedy Jr. had requested an Inspector General investigation into Children's Hospital Colorado over Medicaid billing practices linked to youth hormone prescriptions, adding another layer of pressure on the institution.
The ballot fight also follows earlier legislative skirmishes over youth gender identity in Colorado. In January, Colorado Senate Democrats introduced a custody bill that would have required family courts to evaluate whether parents recognize a minor child's identity in custody determinations. With Proposition 135 now headed to voters, Colorado finds itself at the center of a question other states have so far left to lawmakers rather than the ballot box.
