Proposition 134Male and Female Participation in School and Collegiate Sports
Read the full text of the measure: Blue Book pages 92 to 94 (PDF)
In plain words
Proposition 134 would make every school sports team say who can play on it: boys and men only, girls and women only, or anyone. Students would have to play on the team that matches their biological sex (the sex their body is built around, as the measure defines it), or on a team open to all. It covers schools from elementary school through college. source: Blue Book, p. 55
Before and after
| Question | Today | If Proposition 134 passes |
|---|---|---|
| Who decides which students can play on which team? | Each school, school district and athletic association sets its own policy, following state and federal law | State law sets one rule: teams are for biological males only, biological females only, or open to all |
| Can a student play on a team that matches their gender identity (the gender they know themselves to be)? | Yes. Colorado's anti-discrimination law says public schools and colleges may not keep students out of activities that match their gender identity | No, unless the team is open to all. Students play on the team that matches their biological sex |
| Can a girl play on a boys' team? | Set by each school's policy | Yes, but only if there is no equal girls' team for that sport |
| Which teams are covered? | Not applicable | Teams that play other schools, in-house (intramural) sports and school after-school programs, at public, charter, private and religious schools, and public and private colleges. Not youth leagues run apart from schools |
| Can anyone punish a school for making a team girls-only? | CHSAA rules let it review schools' decisions on transgender students (a December 2025 settlement lets the schools in one lawsuit keep separate teams without CHSAA penalties) | No. Government agencies, licensing or accrediting groups and athletic associations could not investigate or penalize it |
From the official analysis source: Blue Book, p. 55
Example
Illustration only: a high school has a girls' soccer team and a boys' soccer team. Under Proposition 134, a student whose biological sex is male could not join the girls' team, even if she identifies as a girl. A girl could join the boys' baseball team only if the school has no girls' baseball or similar girls' team. The school picks its own way to check each student's biological sex. source: Blue Book, p. 55
Biggest change
- Students would have to play on teams that match their biological sex, or on a team open to all. Today, Colorado law says public schools and colleges may not keep students out of activities that match their gender identity. source: Blue Book, p. 55
Who it affects most: Students on school sports teams whose gender identity is different from their biological sex, and the schools that must write and enforce the new rules.
Cost to the state: Unknown. The Blue Book does not give an amount. It says the state Department of Education could have more work and legal costs if a district does not follow the rule, and that local costs for schools to update their policies are expected to be minimal.
Our plain-words summary at an 8th-grade reading level. Every line points to its source.
What your vote means
Every school team from elementary school through college would be for biological males, biological females, or anyone, and students would play on the team that matches their biological sex.
Schools, school districts and athletic associations would keep setting their own rules on who plays on which team, under current state and federal law.
Our plain-words summary.
The Blue Book's official wording of YES and NO (tap to open)
YES: A “yes” vote on Proposition 134 means that all school-based athletic teams and sports must be designated as being for biological males or biological females only, or as mixed, and requires schools and school districts to adopt policies on sex eligibility for sports.
NO: A “no” vote on Proposition 134 means that individual schools, school districts, and athletic associations may continue to set their own policies in alignment with current state and federal law about who is eligible to participate on a team or in a sport.
Why people want it, and why others object
Why this is on the ballot
- Citizens put this on the ballot by collecting signatures (a citizen initiative). It would change a state law (a statute), not the state constitution, so the legislature could change it later. source: Blue Book, p. 55
- In 2025, eight Colorado schools and school districts sued over the state high school sports group's (CHSAA's) rules and the state anti-discrimination law. They settled with CHSAA in December 2025, but the part about the state law is still in court. In June 2026, the U.S. Supreme Court ruled that federal law (Title IX) lets states keep separate male and female sports based on biological sex. source: Blue Book, p. 55
Why supporters want it
- Females should be able to compete against other females. Allowing biological males to participate on female teams creates an unfair advantage for the males and can prevent female athletes from achieving wins, records, podium spots, and scholarship opportunities. The measure protects the accomplishments of female athletes and creates a consistent, statewide standard for participation on female teams. Without uniform rules, female athletes across the state compete under different policies and conditions, resulting in an uneven playing field. The measure ensures that all female athletes can compete fairly no matter where they live. source: Blue Book, p. 55
- Allowing biological males to participate on female teams or in female sports jeopardizes the safety and physical and emotional boundaries of female athletes. Regardless of one’s gender identity, genetic differences between biological males and biological females can affect physical strength, stature, lung capacity, muscle tone, and growth. Males and females are separated in certain sports due to the physical differences between the sexes and the risk for injury. Beyond the field of play, shared locker rooms raise privacy concerns. The measure creates a reasonable policy grounded in biological sex that promotes the safety of all participants. source: Blue Book, p. 55
Why opponents object
- The measure does not protect fairness; it turns athletic eligibility into a body inspection and manufactures new grounds for discrimination. It could subject many athletes, not just those who are transgender, to uncomfortable physical inspections. Mandating a statewide eligibility standard, but not a clear method for determining eligibility, will require schools and districts to create their own source: Blue Book, p. 55
- School sports should be a space where all kids can build confidence, health, and belonging and have the opportunity to learn teamwork, leadership, and goal setting. Targeting an at-risk group of students by preventing them from playing on teams with their peers and instead requiring them to play on teams that do not match their gender identity leads to harassment, shame, embarrassment, and feelings of isolation and exclusion. The measure’s rigid participation standards apply to kids of all ages and abilities, affecting even young children who just want to play on teams with their friends and peers and are not competing for championships or scholarships. source: Blue Book, p. 55
Who backs each side
Most totals are through October 4, 2026 (Rocky Mountain Voice, Oct 6); some are as of September 21 (Colorado Politics). Spending grows until Election Day. These figures come from news reports of state campaign finance filings and were not checked line by line against the filings.
- For: Protect Kids Colorado (combined total listed under Proposition 133).
- Against: Families Not Politics reported about $1.39 million through Oct 4, including One Colorado Education Fund ($327,000), Cobalt Advocates ($254,000), ACLU ($140,000), and Rose Community Foundation, Planned Parenthood Action Fund and Merle Chambers ($100,000 each).
Sources: Rocky Mountain Voice, Oct 6, 2026 · Colorado Politics, Sept 25, 2026 · Colorado Secretary of State: committees for and against 2026 measures · TRACER campaign finance search
Supporter and opponent arguments are the official ones printed in the Blue Book, written by the Legislative Council's nonpartisan staff after hearing from both sides. Who is registered for and against (Secretary of State) . We don't endorse either side.
At a glance
Our plain-words summary of the official Blue Book analysis. Every line points to its source.
Who it affects
- Students on school sports teams from elementary school through college. This includes public, charter, private and religious schools, and public and private colleges, universities and community colleges. (Blue Book, p. 55 )
- Students whose gender identity is different from their biological sex. They would have to play on teams that match their biological sex, or on a mixed team. (Blue Book, p. 55 )
- It covers teams that play other schools, in-house intramural sports and after-school programs run by schools. It does not cover youth sports and leagues that are separate from schools. (Blue Book, p. 55 )
- Schools and school districts, which must adopt a policy and decide their own way to verify a student's biological sex. (Blue Book, p. 55 )
- The state Commissioner of Education, who must notify a public K-12 district that does not comply and take corrective action if it does not make a good-faith attempt to comply. The measure sets no enforcement for private K-12 schools, colleges, universities or athletic associations. (Blue Book, p. 55 )
- Athletic associations such as the Colorado High School Activities Association (CHSAA). Government agencies, licensing or accrediting groups and athletic associations could not investigate or penalize a school for making a team female-only. (Blue Book, p. 55 )
How many: Unknown. The Blue Book does not give a count of students who would be affected. It says at least seven Colorado schools and school districts have already adopted policies that keep biological males who identify as female out of female sports.
Money: economic and budget impact
- State: more workload and legal costs, by an amount the Blue Book does not estimate, for the Department of Education if a district is intentionally out of compliance and the Commissioner must take action. Legal services come from the Department of Law. (Blue Book, p. 55 )
- State colleges and universities: added costs to adopt or update sports policies. These are assumed to be paid from institutional revenue, such as tuition, fees or athletic department revenue. (Blue Book, p. 55 )
- Local: more workload and possibly more costs for schools, school districts and charter schools that offer sports, to update and carry out their policies. The Blue Book expects these costs to be minimal. (Blue Book, p. 55 )
- Local: school districts may have legal and other costs if the Department of Education takes action for noncompliance. (Blue Book, p. 55 )
- No new tax, no change in state revenue and no effect on TABOR refunds is listed. No budget years are named. (Blue Book, p. 55 )
Every school-based team or sport must be labeled as for biological males only, for biological females only, or mixed. Students must play on teams that match their biological sex or on a mixed team. Biological females may play on a male team if there is no equal female team. This changes state statute, so the legislature can amend it later. The Blue Book says it is unclear how the measure will interact with the Colorado Anti-Discrimination Act.
Schools, school districts and athletic associations keep setting their own policies under current state and federal law. Under the Colorado Anti-Discrimination Act, public K-12 schools, colleges and universities may not exclude students from activities that match their gender identity. A December 2025 settlement lets the schools in that lawsuit keep separate teams for biological males and females without CHSAA penalties, and the challenge to the state law is still ongoing.
Not yet known
- How many Colorado students would be affected, including how many transgender students play school sports.
- How schools would verify biological sex, and what that would cost families or schools.
- A dollar estimate for state or local costs.
- How the measure would fit with the Colorado Anti-Discrimination Act and the ongoing lawsuit over it.
Can it actually be enforced?
Short answer: Partly. Federal law, as the Supreme Court read it in June 2026, lets states do this. But it is a statute that may clash with Colorado's own anti-discrimination law, and it has an enforcement tool only for public K-12 school districts.
- This is a change to state statute, not the constitution. The legislature could amend or repeal it later without another statewide vote. (Blue Book, p. 55 )
- Federal law: on June 30, 2026, in West Virginia v. B.P.J. and Little v. Hecox, the U.S. Supreme Court ruled 6-3 that neither Title IX nor the Equal Protection Clause requires schools to let students play on teams by gender identity instead of biological sex. The ruling lets states separate teams by biological sex but does not require it. So a federal challenge on those grounds would face a high bar. (jurist.org )
- Federal policy points the same way. Executive Order 14201 (February 2025) tells federal agencies to read Title IX as barring biological males from female teams, and the Blue Book says states that do not follow federal policy may face funding cuts. (Blue Book, p. 55 )
- State law conflict: the Colorado Anti-Discrimination Act currently says public schools and colleges may not exclude students from activities that match their gender identity. The Blue Book says it is unclear how the measure would fit with that law, and a federal lawsuit over that part of the law is still ongoing. (Blue Book, p. 55 )
- Enforcement gap: for public K-12 districts, the Commissioner of Education must notify a district that does not comply and then take corrective action. The Blue Book says there is no enforcement mechanism for private K-12 schools, colleges and universities, or athletic associations. (Blue Book, p. 55 )
- How sex is verified is left to each school or district. The measure sets no method, which opponents say could lead to uneven rules across the state. (Blue Book, p. 55 )
Not yet known
- How a Colorado court would resolve the conflict between this measure and the Colorado Anti-Discrimination Act.
- Whether new lawsuits would be filed under the Colorado Constitution if the measure passes.
This is our reading of the cited law, not legal advice. Court outcomes are uncertain.
Official ballot wording
Official ballot wording, word for word (tap to open)
The ballot title, word for word from the 2026 Blue Book.
Shall there be a change to the Colorado Revised Statutes creating new law restricting participation in all K-12 and collegiate school sports based on the participant’s sex as determined by certain aspects of their biological reproductive system, and, in connection therewith, requiring a school, institution of higher education, or athletic association to designate each school or intramural athletic team or sport as male, female, or coeducational; only allowing participants to compete on the team or sport of their designated sex or to compete on a coeducational team; creating an exception to allow a female to participate on a male-designated team or sport if there is no female team available; prohibiting a government entity, licensing or accrediting organization, or athletic association from entertaining a complaint, opening an investigation, or taking other adverse action against a school for maintaining separate teams or sports for females; and providing the commissioner of education with the authority to enforce the proposed initiative for K-12 school districts?
The official analysis
The full Blue Book analysis, word for word (tap to open)
Everything in this section is quoted from the nonpartisan Legislative Council's 2026 State Ballot Information Booklet (the Blue Book). Charts are described in words. Read the full Blue Book (PDF)
Proposition 134 proposes amending the Colorado statutes to:
- require that all elementary through collegiate school-based athletic teams and sports be designated as male-only or female-only based on biological sex, unless the team or sport is designated as open to participation by individuals of any sex or gender;
- require schools and school districts to implement policies to ensure that students are assigned to gender-designated teams that align with their biological sex; and
- prohibit investigations of, or penalties for, a school that designates a team or sport as female-only.
Summary and Analysis of Proposition 134
What does the measure do?
The measure requires that any school-based team or sport be explicitly designated as being:
- for biological males only;
- for biological females only; or
- coeducational or mixed.
Under the measure, students must compete on teams that match their biological sex or on a coeducational team. Biological females are allowed to participate on a team or sport designated for biological males if there is no equivalent female team offered for that sport. Participation on a coeducational or mixed team or sport is open to all. In addition, the measure prohibits any government
entity, licensing or accrediting organization, or athletic association from investigating or penalizing a school for designating a team or sport as being only for biological females.
How does the measure define biological males and females?
The measure defines biological sex in terms of production of reproductive cells. ”Male” is defined as children or adults whose biological reproductive system is organized around the production of sperm cells. “Female” is defined as children or adults whose biological reproductive system is organized around the production of ova, or egg cells. The measure does not impose a specific method for determining or demonstrating biological sex. Individual schools or school districts must determine their own verification procedures.
What teams does the measure apply to?
The measure applies to all teams and sports organized by schools or athletic associations, including teams that compete against other schools, in-house intramural sports, and after-school programs sponsored by schools. Schools include all public, charter, private, and religious school teams and sports from elementary through high school, and all public or private colleges, universities, and community colleges. Athletic associations are defined in the measure as organizations that administer extracurricular athletic competitions for schools. The measure does not apply to youth sports and leagues that operate separately from schools.
The governing body of every school or district must adopt a policy implementing the requirements established by the measure. For public K-12 schools, if a school district does not follow the measure’s requirements, the state Commissioner of Education must first notify the district of its noncompliance. If the school district does not respond to this notification with a good-faith attempt to comply, then the commissioner must take corrective action. The measure does not establish an enforcement mechanism for private K-12 schools, colleges and universities, or athletic associations that do not adhere to the measure’s requirements.
How does the measure interact with state and federal anti‑discrimination law?
The Colorado Anti-Discrimination Act (CADA) prohibits discrimination in employment, housing, and places of public accommodation based on a person's sex, sexual orientation, gender identity, and gender expression. Public K-12 schools, colleges, and universities may not exclude students from extracurricular activities that align with their gender identity, even if their gender identity is different from their biological sex. It is unclear at this time how the measure will impact current state law. At the federal level, Title IX of the Education Amendments of 1972 prohibits sex-based discrimination in federally funded education programs. Courts and presidential administrations have interpreted Title IX in a variety of ways, sometimes including and sometimes excluding gender identity under the definition of “sex.” On February 5, 2025, the President issued Executive Order 14201, “Keeping Men Out of Women’s Sports,” which directs federal agencies to interpret Title IX as prohibiting biological males from participating on teams or in sports designated as being for biological females. States that do not adhere to federal policy may face cuts in federal funding, and state laws or policies that conflict with federal law may face legal challenges from the federal government. At least seven Colorado schools
and school districts have adopted policies restricting biological males who identify as female from participating in female sports. In June 2026, the U.S. Supreme Court ruled that Title IX permits states to adopt laws that maintain separate male and female sports based on biological sex.
How do athletic associations currently address this issue?
The Colorado High School Activities Association (CHSAA), the association that oversees high school sports, recognizes a right for transgender athletes to participate in school activities. Its rules allow CHSAA to review schools’ athletic eligibility decisions for transgender students. In 2025, eight schools and school districts in Colorado filed a federal lawsuit challenging CHSAA rules and CADA requirements related to classification of sports teams by sex. The group of schools and districts and CHSAA reached a settlement agreement in December 2025 that allows schools to maintain separate sports teams and facilities for biological males and biological females without being penalized or sanctioned by CHSAA. However, the portion of the lawsuit challenging CADA is still ongoing.
At the collegiate level, the National Collegiate Athletic Association (NCAA) rules state that competing in female sports is limited to student athletes who are assigned female at birth, and student athletes assigned male at birth cannot receive athletic scholarships designed for females, regardless of their gender identity. The NCAA rules do not apply to intramural collegiate sports.
Arguments For Proposition 134
1) Females should be able to compete against other females. Allowing biological males to participate on female teams creates an unfair advantage for the males and can prevent female athletes from achieving wins, records, podium spots, and scholarship opportunities. The measure protects the accomplishments of female athletes and creates a consistent, statewide standard for participation on female teams. Without uniform rules, female athletes across the state compete under different policies and conditions, resulting in an uneven playing field. The measure ensures that all female athletes can compete fairly no matter where they live.
2) Allowing biological males to participate on female teams or in female sports jeopardizes the safety and physical and emotional boundaries of female athletes. Regardless of one’s gender identity, genetic differences between biological males and biological females can affect physical strength, stature, lung capacity, muscle tone, and growth. Males and females are separated in certain sports due to the physical differences between the sexes and the risk for injury. Beyond the field of play, shared locker rooms raise privacy concerns. The measure creates a reasonable policy grounded in biological sex that promotes the safety of all participants.
Arguments Against Proposition 134
1) The measure does not protect fairness; it turns athletic eligibility into a body inspection and manufactures new grounds for discrimination. It could subject many athletes, not just those who are transgender, to uncomfortable physical inspections. Mandating a statewide eligibility standard, but not a clear method for determining eligibility, will require schools and districts to create their own
separate policies, which will likely lead to unfair and uneven treatment of student athletes across the state. Some athletes may be forced to undergo invasive or expensive testing to prove their biological sex, while others may be able to simply provide a note from a doctor. Certain athletes could even be targeted for additional testing based on their physical strength, appearance, or athletic success.
2) School sports should be a space where all kids can build confidence, health, and belonging and have the opportunity to learn teamwork, leadership, and goal setting. Targeting an at-risk group of students by preventing them from playing on teams with their peers and instead requiring them to play on teams that do not match their gender identity leads to harassment, shame, embarrassment, and feelings of isolation and exclusion. The measure’s rigid participation standards apply to kids of all ages and abilities, affecting even young children who just want to play on teams with their friends and peers and are not competing for championships or scholarships.
Information about the organizations supporting and opposing this measure is available on the Colorado Secretary of State's website:
www.coloradosos.gov/pubs/elections/Initiatives/ballot/contacts/2026.html
Fiscal Impact of Proposition 134
State Spending
Proposition 134 will increase workload and legal costs by an indeterminate amount in the Colorado Department of Education if a school district is intentionally out of compliance with the measure and the Commissioner of Education is required to take remedial action. Legal services are provided by the Department of Law.
In addition, state institutions of higher education will have increased costs to adopt or update policies for interscholastic or intramural athletic programs to align with the requirements in the measure. Any costs are assumed to be paid by institutional revenue, such as tuition, fees, or athletic department revenue.
Local Government Spending
Proposition 134 will increase workload and may increase costs for schools, school districts and charter schools that offer interscholastic or intramural athletic programs to update and implement their policies. These costs are expected to be minimal. To the extent the Colorado Department of Education takes remedial action for noncompliance, legal and other costs may also increase for school districts.
Latest news
Recent reporting from a range of outlets, newest first. We link to it; we don't endorse it.
- 2026-10-06 The Colorado Sun: Meet the woman behind the Colorado ballot measures this year on transgender youth
- 2026-10-02 Colorado Politics: Proposition 134
- 2026-10-01 The Colorado Sun: Proposition 134 explained: Banning transgender kids in Colorado from gendered sports
- 2026-09-25 CPR News: Proposition 134: Male and Female Participation in School Sports
- 2026-09-22 Colorado Newsline: Few trans students play school sports in Colorado. A 2026 ballot measure would ban them.
Coverage of all the statewide measures
- 2026-10-06 Rocky Mountain Voice: What's on your 2026 Colorado ballot: all 14 statewide measures
- 2026-09-25 Colorado Politics: Major donors fuel Colorado ballot measure fights across the state
- 2026-09-25 CPR News: 2026 Colorado state ballot measures voter guide
Full text of the measure
This measure changes existing law. The printed Blue Book shows new wording in capital letters and wording being removed in strikeout type, which we can't reproduce reliably here. Read it in the Blue Book, pages 92 to 94 (PDF) .
Read more
- 2026 Blue Book (PDF) , including the full legal text of the measure
- Colorado Secretary of State: who is registered for and against
- TRACER: Colorado campaign finance filings
What people are saying
Official campaign accounts on each side, and public posts. Links only: nothing here loads from social media sites. We link to posts; we don't endorse them.
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