I-638 passes, will bar transgender girls from girls’ school sports

Initiative 638 has passed, which will bar transgender girls from girls’ school sports. The Associated Press called the measure.

The initiative passed with 56.6% in favor and 43.3% opposed, according to The Associated Press. However, Democrats are working to overturn it.

I-638, sponsored by the political committee Let’s Go Washington, requires students who compete in girls’ sports to have a health care provider verify their biological sex.

What the initiative does

The measure requires school districts and nonprofit organizations that run sports with separate boys’ and girls’ competitions to “prohibit biologically male students from competing with and against female students.” Students who want to compete in girls’ events would have to submit a statement signed by a health care provider verifying their biological sex.

The initiative said the provider may verify sex as part of a routine sports physical, relying only on reproductive anatomy, genetic makeup, or normal naturally produced testosterone levels. It doesn’t say how a provider should gather that information, and schools may offer coed activities open to any student. The requirement applies to students competing in girls’ sports, not boys’.

How things work now

The Washington Interscholastic Activities Association’s (WIAA) rules let students take part in programs consistent with their gender identity or the gender they most consistently express. In April, WIAA member schools voted 29-24 to adopt an advisory proposal that would limit girls’ sports to biological females. The association said it wouldn’t implement the proposal because it conflicts with state law.

State officials estimated five to 10 transgender athletes compete among more than 200,000 student-athletes statewide, though no official data exists. Let’s Go Washington spokesperson Hallie Herzberg said the numbers don’t change its argument, and that one girl losing a podium spot “is enough for us to take action.”

The legislature’s Democratic leaders didn’t act on the initiative this year, so it went to the ballot.

Similar laws are on the books in 27 states, and the U.S. Supreme Court ruled this summer that state laws barring transgender athletes from girls’ teams don’t violate the 14th Amendment or Title IX. The ruling doesn’t require states to adopt them.

Where the sides disagreed

Supporters of I-638 said the measure protects fair competition and opportunities for girls and adds one step to an existing process. Herzberg described it as restoring a sex checkbox removed from the sports physical form in 2019.

Opponents of I-638 argued the verification requirement would reach all girls who play, not only transgender girls.

Dr. Libby Loft, a Spokane family physician who opposed the measure, said the initiative’s text bars using a birth certificate, leaving providers with an anatomical exam, a testosterone test, or chromosome testing — the last two costing $162 and $1,310 without insurance.

Let’s Go Washington disputed that the measure would require invasive or expensive exams.

Opponents of I-638 included Governor Bob Ferguson, Senator Patty Murray, the Seattle School Board, the King County Council, the Washington State PTA, the Washington State Nurses Association, and the League of Women Voters.

Supporters of I-638 include the groups Democrats for an Informed Approach to Gender, the Women’s Liberation Front, and Moms for Liberty.

WIAA has said it is committed to Washington state law and will honor any changes made by I-638.

This story was originally published on Nov. 3, 2026. It has been updated and republished since then.

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