Washington State voters will decide the fate of a ballot initiative that would require girls from kindergarten through high school to undergo sex-verification testing before playing school sports — a measure critics call the most extreme of its kind in the country.

IL26-638 would bar transgender athletes from girls’ teams by mandating that a health-care provider certify a player’s sex assigned at birth, using genetic screening, testosterone testing or an examination of reproductive anatomy as part of the annual sports physical every young athlete already undergoes, reported The Cut.