The department’s civil rights office said the policy violates federal civil rights law, which guarantees equal education for women, in the 45-page letter to the Connecticut Interscholastic Athletic Conference (CIAC).
In response, the CIAC said its policy protected transgender athletes from discrimination.
“Connecticut law is clear and students who identify as female are to be recognized as female for all purposes — including high school sports,” the athletic conference said in a statement.
“To do otherwise would not only be discriminatory but would deprive high school students of the meaningful opportunity to participate in educational activities … based on sex-stereotyping and prejudice,” it said.
The ruling came in response to a federal lawsuit, filed by three female track runners, from the state of Connecticut, who argued they were put at a physical disadvantage competing against trans athletes.
It solidified the federal government’s stance, in the controversial debate that is playing out in states nationwide.
Connecticut is one of 18 US states that allows trans high school athletes to compete without restrictions, according to Transathlete.com, a website that compiles information on trans inclusion in athletics.
The Education Department said it would either withhold federal funding for the Connecticut school districts where the runners competed, or refer the cases to the US Department of Justice.
The letter said the school’s policy has “denied female student-athletes athletic benefits and opportunities” including higher level competitions, recognition and visibility to colleges.
Male-to-female trans athletes have been allowed to compete in the International Olympic Games since 2016, if their testosterone levels meet a certain low level for a year.
Idaho became the first US state to pass a law barring trans high school athletes from playing in sports leagues that differ from their gender at birth. Several other states are considering similar restrictions. The lawsuit was filed in February by the three runners, against the CIAC, and a number of local boards of education.
-Matthew Lavietes – Thomson Reuters Foundation