A transgender student challenged West Virginia’s law limiting participation on girls’ interscholastic sports teams to students classified as biologically female. The district court entered summary judgment for the State on the student’s Title IX and Equal Protection Clause claims, but the Fourth Circuit reversed on the Title IX claim and remanded the equal-protection claim for further proceedings. The Supreme Court reversed. It held that Title IX permits schools to maintain separate male and female athletic teams and to determine eligibility for female teams according to biological sex. It further held that West Virginia’s sex-based classification satisfies intermediate scrutiny because preserving competitive fairness and athletic safety are important governmental interests and limiting girls’ teams to biological females is substantially related to those interests. The Equal Protection Clause does not require individualized judicial assessments of whether particular transgender athletes retain competitive advantages after puberty blockers or hormone treatment.