The Supreme Court ruled Tuesday that states can legally bar transgender girls and women from participating in female school sports teams. Justice Brett Kavanaugh wrote that separate teams for biological males and females are reasonable due to inherent physical differences. The decision upheld Idaho's HB 500 and West Virginia's law, finding no Title IX violation.

All nine justices agreed on the Title IX conclusion, though Justices Sotomayor, Kagan, and Jackson dissented on equal protection grounds. Since Idaho's law was first passed, 26 additional states have enacted similar restrictions. Major sports organizations including the NCAA and USOPC have already adopted policies limiting transgender women's competition in female categories.

The ruling specifically addresses only the Idaho and West Virginia laws. Athletes in 21 states permitting transgender participation remain unaffected, as the Court stopped short of mandating nationwide bans. However, ongoing litigation in Connecticut could force the issue further, while President Trump's February 2025 executive order faces separate legal challenges.

Reaction split along expected lines. New York Liberty's Breanna Stewart called the decision unfair to transgender athletes, while Idaho state Rep. Barbara Ehardt declared victory for women in sports. The Education Department launched multiple investigations into schools and athletic associations regarding transgender participation policies.