The case centers on B.P.J., an 11-year-old transgender girl who signed up for school sports at a new middle school in West Virginia. The state bars students from competing on teams that do not match their biological sex. B.P.J., through her mother Heather Jackson, argues that exclusion violates both Title IX and the Equal Protection Clause. West Virginia, joined by the federal government as amicus supporting the state, contends that biological sex distinctions in athletics are expressly authorized by Title IX's text, the Javits Amendment, and longstanding regulations — and that the law does not classify on the basis of transgender status at all.
West Virginia Solicitor General Michael R. Williams opened by arguing that the state's law mirrors the language of federal regulations that have authorized sex-separated sports teams since the 1970s, and that those regulations have never been challenged in this case. He argued that "sex" in Title IX, as understood in 1972 and when the Javits Amendment passed in 1974, meant biological sex, and that the state's law satisfies both rational basis and intermediate scrutiny because biological sex substantially relates to athletic performance.
Principal Deputy Solicitor General Hashim M. Mooppan, arguing for the United States as amicus, urged the Court to resolve the Title IX claim narrowly: the regulations expressly authorize sex-separated teams, sex in those regulations means biological sex in the reproductive biology sense, and therefore whether testosterone suppression eliminates any physical advantage is legally irrelevant under the regulations' plain terms. Justice Barrett pressed both advocates on whether, because of the Javits Amendment and the respondent's concession that Title IX permits sex-separated sports, the Court could avoid the similarly situated argument and the broader hypotheticals about classrooms and chess clubs entirely — and Mooppan agreed the Court could do so.
Joshua A. Block, arguing for B.P.J., told the Court that Title IX and the Equal Protection Clause protect everyone, and that if the evidence shows no relevant physiological differences between B.P.J. and other girls, there is no basis to exclude her. He emphasized that B.P.J. had not been through male puberty and had also undergone a female hormonal puberty with accompanying physiological changes, and he urged the Court to remand for factual development rather than issue a broad legal ruling. He also clarified that the Fourth Circuit's theory — that competitive advantage is legally irrelevant to the Title IX claim — had never been his argument, and said he had no objection to vacating the summary judgment entered in B.P.J.'s favor below.
Justice Kavanaugh pressed Block on the zero-sum nature of competitive sports — cuts, starting lineups, and college recruiting — and asked whether a ruling that sex in Title IX means biological sex would effectively foreclose states like California from allowing transgender girls to compete on girls' teams. Mooppan said he did not think the narrowest ground for ruling here would tie California's hands, because California could still argue that the regulations permit accommodation on the basis of gender identity even if sex means biological sex. Block separately argued the Court should not issue a definition of sex at all, and should not hold that Title IX creates a right to sex-separated teams, in order to preserve flexibility for states making different policy choices.
Justice Jackson pressed Williams and Mooppan on whether the law, while facially a sex classification, operates as a second-order classification against transgender girls specifically — since cisgender girls can play on teams consistent with their gender identity while transgender girls cannot. Williams responded that the law is indifferent to gender identity and that the facial classification is between boy and girl. Justice Sotomayor raised the hypothetical that if science showed no physiological difference between men and women full stop, the governmental interest in exclusion would fall away — a premise Williams ultimately accepted, though he disputed the factual premise itself.
The case, docketed as No. 24-43, was submitted after argument on January 13, 2026.