HARRISBURG, Pa. — The Trump administration said Monday that the University of Pennsylvania violated laws guaranteeing women equal opportunities in athletics by letting a transgender swimmer compete on the school’s women’s team and into team facilities.

The administration’s statement does not name Lia Thomas, the transgender swimmer who last competed for the Ivy League school in Philadelphia in 2022 and was the first openly transgender athlete to win a Division I title that year — an award Thomas now faces losing.

But the investigation opened in February by the U.S. Department of Education’s Office for Civil Rights focused on Thomas, who became a leading symbol of transgender athletes and a prominent political target of Republicans and President Donald Trump.

The department said Penn violated Title IX, which bars sex discrimination in schools and colleges, by “denying women equal opportunities by permitting males to compete in women’s intercollegiate athletics and to occupy women-only intimate facilities.”

Penn had no immediate comment Monday, but Penn has said in the past that it always followed NCAA and Ivy League policies regarding student participation on athletic teams, both when Thomas swam and currently.

The department said Penn has 10 days to voluntarily resolve the violations or risk prosecution. The department wants Penn to issue a statement saying that it will comply with Title IX; effectively strip Thomas of any awards or records in Division I swimming competitions; and apologize to each female swimmer “whose individual recognition is restored expressing an apology on behalf of the university for allowing her educational experience in athletics to be marred by sex discrimination.”

The Trump administration in March suspended approximately $175 million in federal funding for Penn over its decision to let Thomas compete, the White House has said. The Ivy League school’s federal money came from the Defense Department and the Department of Health and Human Services.

In 2022, the NCAA used a sport-by-sport approach to allowing transgender athletes to participate, deferring to an individual sport’s national governing organization, international federation or prior established International Olympic Committee criteria.

Thomas competed under those guidelines, which allowed female transgender swimmers who had completed one year of hormone replacement therapy to compete.

The NCAA changed its policy the day after Trump signed an executive order on Feb. 5 that was intended to ban transgender athletes from competing in girls’ and women’s sports. That ended its sport-by-sport practice in favor of a blanket policy that allows only athletes assigned female at birth to participate in women’s sports.

The Education Department also opened reviews of San Jose State University volleyball, Denver Public Schools, Portland Public Schools, Oregon School Activities Association and the Massachusetts Interscholastic Athletic Association. It also sued the state of Maine to force it to ban transgender athletes from girls’ and women’s sports or face prosecution.