Schools and colleges across the U.S. would be forbidden from enacting outright bans on transgender athletes under a proposal released Thursday by the Biden administration, but teams could create some limits in certain cases — for example, to ensure fairness.

The proposed rule sends a political counterpunch toward a wave of Republican-led states that have sought to ban trans athletes from competing in school sports that align with their gender identities. If finalized, the proposal would become enshrined as a provision of Title IX, the landmark gender-equity legislation enacted in 1972.

It must undergo a lengthy approval process, however, and it's almost certain to face challenges. While opponents sharply criticized the proposal, some advocates for transgender athletes were concerned that it did not go far enough.

The proposal comes on the same day that the Supreme Court said a 12-year-old transgender girl in West Virginia can continue competing on her middle school track and cross-country teams while legal battles over the state's transgender law continue. The law bans transgender athletes from female teams.

All told, at least 16 states now have bans in effect covering at least high school interscholastic sports. Some also extend to intramural, club or college sports. Enforcement of bans in at least three other states has been put on hold by courts, and one more has adopted a ban that doesn't take effect until July.

Under the Education Department's proposed rule, no school or college that receives federal funding would be allowed to impose a "one-size-fits-all" policy that categorically bans trans students from playing on sports teams consistent with their gender identity. Such policies would be considered a violation of Title IX.

Still, the proposal leaves room for schools to develop team eligibility rules that could ultimately result in restrictions around trans athletes' participation.

That would be allowed only if it serves "important educational objectives," such as fairness in competition and reduction of injury risks.

Any limits would have to consider the sport, the level of competition and the age of students. Elementary school students would generally be allowed to participate on any teams consistent with their gender identity, for example. More competitive teams at high schools and colleges could add limits, but those would be discouraged in teams that don't have tryouts or cuts.

"Every student should be able to have the full experience of attending school in America, including participating in athletics, free from discrimination," said Miguel Cardona, Biden's education secretary, in a statement.

Biden's administration used "fairness of competition" as criteria, which has been part of the debate both in the U.S. and globally. But officials offered no specifics on how this could be done.

Of the tens of millions of high school students in the U.S., about 300,000 youth between the ages of 13 to 17 identify as transgender, according to a 2022 study from the Williams Institute, a think tank at UCLA focused on LGBTQ+ issues. The number of athletes within that group is much smaller; a 2017 survey by Human Rights Campaign suggested fewer than 15% of all transgender youth play sports.

Asked about the proposal, Bobbie Hirsch, a transgender man and sophomore on the Wayne State men's fencing team, said "anything helps." But he feared the language in the rule would make it easier for schools to tell transgender athletes they can't play on a team. "That's the direction things have been going," he said in a phone interview.

Hirsch competed on the women's team in the 2021-22 season, and began transitioning socially in high school and medically last summer.

Eli Bundy, an 18-year-old transgender resident of Charleston, South Carolina, said they welcomed the proposal but were stopping short of celebrating.

"I have a hard time feeling relief when positive stuff happens at the national level, because there's still so much at the state level from the South Carolina Legislature that is antagonistic and sends a really harmful message to trans youth," said Bundy, who testified in 2021 against the state's ban on transgender students' participation in girls' or women's sports at public schools and colleges.

Asked about the state bans now in place, a senior Education Department official briefing reporters on condition of anonymity said Title IX is the law of the land and officials would work to ensure it's being followed in all the states.

In the West Virginia case, the Supreme Court refused to undo an appeals court order that made it possible for the girl, Becky Pepper-Jackson, to continue playing on her school's teams. The state's law on transgender athletes defines male and female by looking to the student's "reproductive biology and genetics at birth." It applies to middle and high schools, as well as colleges.

Elsewhere, Republican lawmakers insisted they had the right to set policies in their states. The Biden administration's announcement came a day after Kansas lawmakers succeeded in overriding Democratic Gov. Laura Kelly's third veto in three years of a bill to ban transgender female athletes from girls' and women's sports.

"At what point does the federal government not understand the U.S. Constitution that says we have states' rights?" said Republican state Rep. Brenda Landwehr, of Wichita. "We can make decisions on our own."

Critics argue transgender athletes have an advantage over cisgender women in competition. Last year, Lia Thomas became the first transgender woman to win an NCAA swimming title. College sports' governing body, however, adopted a sport-by-sport approach to transgender athletes in January 2002, though recently the NCAA's board decided it won't be fully implemented until 2023-24.

The NCAA released a statement Thursday night saying: "The NCAA's current transgender student-athlete participation policy aligns with the Olympic movement and balances fairness, inclusion and safety for all student-athletes. That policy remains in place while the lengthy Title IX regulatory process plays out."

At the same time, international sports-governing bodies are instituting policies that ban all trans athletes from competing in track and field and effectively ban trans women from swimming events.

Donna de Varona, a two-time Olympic gold medalist in swimming and a member of the Women's Sports Policy Working Group, said her hope is to find a "nuanced approach" to finding space for transgender athletes while allowing for Title IX to make sure girls and women have "fairness, opportunity and safety."

"There's plenty of room. ... Why does it have to be in the women's category? We're already being compromised in our reproductive rights and now we have the other spectrum with sports," de Varona said in a phone interview.

Sasha Buchert, Lambda Legal senior attorney and director of the group's Nonbinary and Transgender Rights Project, said the proposed rule provided "critical recognition of the importance of participating in sports for transgender youth." At the same time, she expressed concern about whether it would eliminate discrimination against transgender students.

But an attorney for cisgender runners decried the proposal as "a slap in the face to female athletes who deserve equal opportunity to compete in their sports."

"The Biden administration's rewriting Title IX degrades women and tells them that their athletic goals and placements do not matter," said Christiana Kiefer, senior counsel at Alliance Defending Freedom. She represented Connecticut runners who sued over the participation of two transgender girls in track and field events.

President Joe Biden's administration has made it a priority to bolster the rights of trans students. Last year it proposed a separate federal rule that for the first time would extend Title IX rights to LGBTQ+ students, broadly protecting them from discrimination in education.

That rule — which drew more than 240,000 comments from the public and sharp opposition from conservatives — is expected to be finalized as soon as next month.

The new proposal doesn't offer examples of acceptable limits that could be placed on school sports, but it clarifies that restrictions couldn't be directed at trans students only. Schools would be left to navigate that tricky legal terrain, with the knowledge that any violation could bring a federal civil rights investigation or lawsuits.

Schools that choose to impose limits must "minimize harms" to students who lose out on athletics opportunities, the proposal says. If a school can achieve objectives like fairness in ways that cause less harm, then the school could be deemed to be violating Title IX.

"Preventing students from participating on a sports team consistent with their gender identity can stigmatize and isolate them," according to background information provided by the administration. "This is different from the experience of a student who is not selected for a team based on their skills."

Schools that violate Title IX can face penalties up to a complete loss of federal funding, although no school has ever been dealt that punishment.