What the state laws do
Since 2020, more than two dozen states have passed laws requiring athletes in public schools, and in some cases public colleges, to compete on teams that match the sex listed on their original birth certificate. The statutes generally apply to girls' and women's teams, with most permitting transgender boys to try out for boys' teams. Penalties and enforcement mechanisms vary; some laws allow students or schools to sue if they believe the rules have been violated.
The federal laws in play
Two federal authorities sit at the center of the legal fight. Title IX of the Education Amendments of 1972 bars sex-based discrimination in federally funded schools and is the statute used to require equal athletic opportunities for girls and women. The Fourteenth Amendment's Equal Protection Clause prohibits states from denying any person equal protection of the laws, and courts apply heightened scrutiny to classifications based on sex.
How Bostock figures in
In Bostock v. Clayton County (2020), the Supreme Court ruled 6-3 that firing an employee because they are transgender is sex discrimination under Title VII, the federal workplace bias law. The majority opinion, written by Justice Neil Gorsuch, said it is impossible to discriminate against someone for being transgender without taking their sex into account. The Court has not decided whether the same reasoning extends to Title IX or to sex-separated sports.
The case for the state laws
Supporters argue that male puberty produces physiological differences—including in muscle mass, bone density, and lung capacity—that can persist after hormone therapy and create competitive advantages in many sports. They contend that Title IX was enacted in part to guarantee female athletes fair competition and equal access to scholarships, records, and roster spots, and that sex-based categories are necessary to preserve those opportunities. Several governing bodies in elite swimming, track, and cycling have adopted similar restrictions, which proponents cite as evidence the approach is mainstream.
The case against the state laws
Opponents argue the laws single out a small group of students for exclusion and violate Title IX by denying them participation on the basis of sex, including gender identity. They say the Equal Protection Clause forbids states from drawing classifications that disadvantage transgender people without a sufficient justification, and they point to medical organizations that say categorical bans are not necessary to ensure fair competition. Critics also note that few transgender athletes compete at the K–12 level and that case-by-case eligibility rules, like those long used by some athletic associations, can address competitive concerns.
What the Supreme Court will decide
The Court agreed to hear challenges to laws in West Virginia and Idaho. Lower courts had blocked enforcement against individual transgender plaintiffs, and the justices will consider whether the statutes are consistent with Title IX and the Fourteenth Amendment. A ruling could clarify whether states have authority to define eligibility for sex-separated school sports, or whether federal law and the Constitution require schools to allow transgender students to compete according to their gender identity.
Why states differ
Education policy in the United States is largely shaped at the state and local level, and athletic eligibility rules have traditionally been set by state high school associations. That has produced a patchwork: some states require participation based on birth-certificate sex, others permit it based on gender identity, and others leave the question to individual schools or athletic bodies. The Supreme Court's ruling could narrow that variation or leave much of it intact.