Girls who play school sports in Bellevue will need a health care provider to verify their biological sex before competing, under a statewide initiative that passed Nov. 3.

Initiative 638 won 56.6% of the vote, according to MyNorthwest, with The Associated Press calling the measure on Wednesday, Nov. 4, after two days of vote counting. The law is set to take effect Dec. 3, when the state certifies the election.

But whether Bellevue School District 405 coaches and athletic directors will actually have to enforce the new rules by then is unclear.

Washington State Democratic Party Chair Shasti Conrad said in a statement Thursday that the party believes I-638 "is unconstitutional on its face" and will "support organizations planning to challenge it in court."

The ACLU of Washington said it is "exploring all potential next steps to uphold the rights of transgender girls," according to a statement the organization provided to KATU News.

What the law requires

Under I-638, all girls who want to compete in K-12 girls' sports must submit a statement from a health care provider verifying what the initiative calls their "biological sex."

The verification must be based on at least one of three criteria: reproductive anatomy, genetic makeup, or naturally produced testosterone levels, Axios Seattle reported.

The initiative does not specify how a provider should gather that information. It bars the use of a birth certificate, according to MyNorthwest, leaving providers with a physical exam, a testosterone test, or chromosome testing.

Dr. Libby Loft, a Spokane family physician who opposed the measure, said the last two options cost $162 and $1,310 without insurance.

Let's Go Washington, the political committee that sponsored I-638, disputed that the measure would require invasive or expensive exams.

Spokesperson Hallie Herzberg described it as restoring a sex checkbox removed from the sports physical form in 2019.

The requirement applies only to girls' sports, not boys'. Schools may still offer coed activities open to any student.

How WIAA plans to respond

The Washington Interscholastic Activities Association (WIAA), which governs middle- and high-school athletics statewide, said in a statement to KATU News that its Executive Board "has the authority and would adjust language as necessary to comply with updated state law."

WIAA's current rules, set in the 2007-08 school year, let students play on teams matching their gender identity.

The association's handbook does not require visual checks of girls' genitals, DNA testing, or hormone testing as part of the required sports physical, Axios reported.

State officials estimated five to 10 transgender athletes compete among more than 200,000 student-athletes statewide, though no official count exists.

Court challenge looms

Conrad called the result "incredibly disheartening" and said I-638 rolls back protections that have existed in Washington law for 20 years. The state party said the fight over the measure "is just beginning."

Opponents had argued I-638 discriminates against transgender students and imposes requirements on all girls who participate in school athletics.

No Hate in Washington State, which opposed the initiative, said in a Nov. 4 statement that the "measure has the potential to harm any girl who wishes to play sports through its invasive exam requirements."

The measure passed in 36 of 39 counties, according to the Bellevue Reporter. It failed in King, Jefferson and San Juan counties.

Similar laws exist in 27 states, and the U.S. Supreme Court ruled this summer that state bans on transgender athletes in girls' sports do not violate the 14th Amendment or Title IX, according to MyNorthwest.

County canvassing boards are expected to certify results by Nov. 24. If no court injunction is issued, I-638 takes effect Dec. 3.