Idaho Gov. Brad Little signed the law, HB 500, making Idaho the first state to impose an outright ban on participation of transgender athletes and the only one with a statewide law regulating transgender and intersex athletes in the country. The lawsuit was filed on behalf of a track athlete at Boise State University who is transgender and a junior at Boise High School who is cisgender and concerned about being subjected to invasive "sex verification" testing under the new law.

"We're suing because HB 500 illegally targets women and girls who are transgender and intersex and subjects all female athletes to the possibility of invasive genital and genetic screenings," said Gabriel Arkles, senior staff attorney with the ACLU's LGBT & HIV Project. "In Idaho and around the country, transgender people of all ages have been participating in sports consistent with their gender identity for years. Inclusive teams support all athletes and encourage participation—this should be the standard for all school sports."