Any school or college that receives federal funding—which is nearly all public schools and most colleges—would be barred from letting people born male compete on sports teams designated for women or girls. This would be enforced through Title IX, the federal law that bans sex discrimination in schools that get government money, by treating mixed participation itself as a violation of that law. The bill defines a person's sex for this purpose based on their reproductive biology and genetics at birth, not their gender identity. Schools that don't comply would risk running afoul of Title IX, which can put their federal funding at stake.