Most state girls'-sports laws reach further than I-638, except in verifying every girl.

Five-second answer

Misleading. Most state laws go further on scope and enforcement; I-638 is strictest only in medically verifying every girl. Our coding of all 28 enacted state laws and regulations from their official texts shows most reach college sports and let students sue, which I-638 does not, while only I-638 requires a provider's anatomy, genetic or hormone check for every girl.

One-minute summary

The evidence

The conclusion rests on the combined record. Expand each item to see its role and limitations.

Common questions

Conclusion

Whether a measure is extreme depends on what is measured, so we defined it: a measure is more extreme on a dimension if it reaches more students or schools, demands more of each athlete, or enforces harder. We coded eight such dimensions from the official text of all 28 enacted state measures (27 laws and Alaska's regulation) and of I-638. On scope and enforcement, I-638 is narrower than most. It amends only Washington's K-12 school statutes, while 25 of the 28 state measures also cover college sports. It creates no right to sue, while 24 let harmed students sue (20 with damages or full relief, four limited to injunctions or to colleges). It adds no penalty on schools, while three withhold state funds or postseason play. It does not bar girls from boys' teams, which six states also do. Like 20 of the 28, its text sets no grade floor; eight laws start at grade 5 or later. On verification, I-638 is the outlier, and that is the dimension the No campaign names. It is the only measure that requires every girl entering girls' sports to bring a health care provider's statement, and the only one that limits that check, for everyone, to reproductive anatomy, genetic makeup or testosterone. Fourteen state laws state no verification method, 11 rely on the birth certificate, Oklahoma requires an annual parent affidavit for every athlete, and Nebraska requires a doctor-signed document for every athlete, boys included, without naming a medical basis. Idaho's law uses I-638's three bases almost word for word, but only when a particular student's sex is disputed. Florida's 2021 House bill used the same words for disputes and was replaced by a birth-certificate rule before it became law. The birth-certificate comparison is not like for like. All 11 states that rely on the birth certificate specify the original certificate issued at or near birth. In Washington, the sex on a birth certificate can be changed: since January 27, 2018, WAC 246-490-075 has let an adult, or a parent for a minor, change the designation to M, F or X, and for a minor the application needs a provider's statement that the change is consistent with the minor's identity. A Washington certificate therefore shows the current designation, which may not be the sex recorded at birth. Saying that other states accept birth certificates and I-638 does not compares a document that records sex at birth with one that may not. So the claim takes one real distinction, universal medical verification of girls, and presents it as the measure being the most extreme overall. A voter reading it would likely conclude that I-638 reaches further than other states' laws in general, which the texts contradict on most dimensions. Its campaign's stated reason, that the measure targets girls with genital exams, rests on a reading our separate check rates False: the text lets a provider rely on genetics or testosterone instead. We rate the claim Misleading rather than False because the verification difference is real and the word 'extreme' can fairly be applied to it. Confidence is Moderate. The coded facts are checkable in the official texts, but how to weigh one dimension against another is a judgment, and implementing rules, which we did not review, may make some states stricter in practice than their statutes. Some codified pages could not be fetched, so a few rows rest on enrolled bill text. We found no enacted law and no bill that required a medical exam of every girl, but our search of failed bills was not exhaustive.

Related fact checks

• Related claim: Initiative 638 requires a doctor's sex verification, not a genital exam. — FactHub rates the claim that I-638 will require genital examinations False (high confidence): Initiative 638 requires a doctor's sex verification, not a genital exam. This links to the version that was current when this fact check was written. Read the latest version.
• Related claim: Under I-638, a birth certificate alone can't prove a girl's sex for sports. — FactHub rates the No claim that I-638 bans parents from using birth certificates Misleading: under I-638, a birth certificate alone can't prove a girl's sex for sports, but the text never mentions birth certificates.
• Related claim: The IOC, World Athletics, the WTA and federal policy now restrict the female category. — FactHub rates the Yes claim that federal law, the WTA, World Athletics and the IOC protect the female category Mostly true: the IOC, World Athletics, the WTA and federal policy now restrict the female category, though no federal statute requires it.

How we checked

1. Defined the claim: whether I-638 goes further than every other U.S. measure of its kind, and defined 'extreme' as reaching more students or schools, demanding more of each athlete, or enforcing harder.
2. Listed every state with a statute or state regulation limiting girls' school teams to students of female sex, checked against the Movement Advancement Project's tracker (27 laws plus Alaska's regulation).
3. Read each measure's official text and coded eight dimensions: college coverage, private right of action, penalties on schools, restrictions on girls joining boys' teams, grade floor, routine proof required, provider sign-off, and the bases for verification. The coded table, the verbatim passages and the comparison script are in the dataset.
4. Read I-638's filed text and compared it row by row; checked the legislative history of bills that used the same verification words.
5. Read the No campaign's own explanation of the claim and the Supreme Court's June 30, 2026 opinion for legal status.
6. Recorded the limits of each line of evidence, including unreviewed association rules and single-coder coding.

Editorial note: Scope: this article rates the No campaign's pamphlet heading as a comparison with other U.S. state laws and regulations of the same kind. It does not judge whether any of these laws is wise or fair. 'Stricter' in the dataset and chart is a description of reach, not of merit. Athletic-association policies that are not state law (Virginia, Pennsylvania, Wisconsin) and federal executive policy are outside the comparison. Our state coding was done by one coder and has not been double-coded. No external specialist review has been recorded.

Sources

Sources are labeled by kind, with what this fact check takes from each, so readers can check the evidence independently.

1. Government Washington Secretary of State. Initiative Measure No. IL26-638, filed text (filed June 2, 2025)

   The full text of the measure as filed; Section 3 holds the eligibility and verification rules.

   Reliability: The official filed text posted by the Secretary of State. It is the measure itself; the sponsor wrote it.

   • Qualifies: Every student who elects to enter female-only competition must provide a provider-signed statement verifying her sex as part of the routine sports physical; nothing comparable applies to boys' teams.

     What the source says

     A student who elects to participate in individual or team competition activities intended for female students only governed under subsection (1) of this section shall provide, as part of the required routine sports physical examination, a health examination and consent form or other statement signed by the student's personal health care provider that verifies the student's biological sex,

     Sec. 3(2)

   • Qualifies: The provider may rely only on anatomy, genetic makeup or testosterone; a birth certificate is not a listed basis.

     What the source says

     relying only on one or more of the following: The student's reproductive anatomy, genetic makeup, or normal endogenously produced testosterone levels.

     Sec. 3(2)

   • The act amends only Washington's K-12 school statutes; it has no college provision.

     What the source says

     AN ACT Relating to defending equity in interscholastic sports; amending RCW 28A.600.200 and 28A.640.020; adding a new section to chapter 28A.600 RCW; and creating new sections.

     Title, p. 1
2. Government Idaho Legislature. Idaho Code 33-6203, Designation of athletic teams

   Idaho's 2020 Fairness in Women's Sports Act, the first such law, including its dispute-only verification clause.

   Reliability: Official codified statute published by the Idaho Legislature.

   • Idaho requires a provider's statement only to resolve a dispute about a student's sex.

     What the source says

     A dispute regarding a student's sex shall be resolved by the school or institution by requesting that the student provide a health examination and consent form or other statement signed by the student's personal health care provider that shall verify the student's biological sex.

     33-6203(3)

   • Qualifies: Idaho's bases are almost word for word I-638's: anatomy, genetic makeup or testosterone.

     What the source says

     The health care provider may verify the student's biological sex as part of a routine sports physical examination relying only on one (1) or more of the following: the student's reproductive anatomy, genetic makeup, or normal endogenously produced testosterone levels.

     33-6203(3)
3. Government Idaho Legislature. Idaho Code 33-6205, Cause of action

   Idaho's private right of action for students harmed by a violation.

   Reliability: Official codified statute published by the Idaho Legislature.

   • Idaho lets harmed students sue for damages, including psychological harm, and attorney's fees; I-638 creates no such right.

     What the source says

     Persons or organizations who prevail on a claim brought pursuant to this section shall be entitled to monetary damages, including for any psychological, emotional, and physical harm suffered, reasonable attorney's fees and costs, and any other appropriate relief.

     33-6205(4)
4. Government Nebraska Legislature. LB 89 (2025), Stand With Women Act, slip law

   Nebraska's 2025 law, the only enacted measure requiring a doctor-signed document from every athlete.

   Reliability: Official slip law published by the Nebraska Legislature; codified section numbers were not yet available.

   • Qualifies: Nebraska requires every athlete on a boys' or girls' team to give the school a doctor-signed document confirming sex, without naming a basis.

     What the source says

     In order to participate in an interscholastic athletic team or sport that is designated for males, men, or boys or designated for female, women, or girls … confirmation of such student's sex on a document signed by a doctor or signed under the authority of a doctor.

     Sec. 4(5)
5. Government Oklahoma Legislature. SB 2 (2022), enrolled, codified at 70 O.S. 27-106

   Oklahoma's Save Women's Sports Act.

   Reliability: Enrolled bill text published by the Oklahoma Legislature.

   • Qualifies: Oklahoma requires a yearly parent affidavit of sex at birth for every athlete, a routine requirement but not a medical one.

     What the source says

     Prior to the beginning of each school year, the parent or legal guardian of a student who competes on a school athletic team shall sign an affidavit acknowledging the biological sex of the student at birth.

     Sec. 1(D)
6. Government Kentucky General Assembly. KRS 156.070

   Kentucky's statute on interscholastic athletics, including its 2022 sex-designation rule for grades 6 through 12.

   Reliability: Official statute text published by the Legislative Research Commission.

   • Kentucky accepts a sworn affidavit from the provider who did the sports physical, but only as an alternative to the original birth certificate.

     What the source says

     An affidavit signed and sworn to by the physician, physician assistant, advanced practice registered nurse, or chiropractor that conducted the annual medical examination required by paragraph (e) of this subsection under penalty of perjury establishing the student's biological sex at the time of birth;

     KRS 156.070(2)(g)2.b.
7. Government Georgia General Assembly. SB 1 (2025), Riley Gaines Act, House committee substitute LC 49 2383S

   Georgia's 2025 law on sex designation in school and college sports.

   Reliability: Bill text published by the Georgia General Assembly; this is the House substitute that matches the enacted act as far as we could check.

   • Georgia's law expressly does not authorize visual inspection of a student's external sex organs, while allowing medical records.

     What the source says

     Nothing in this subsection shall be construed to authorize a covered entity or an athletic association, as such term is defined in Code Section 20-2-316, to verify or confirm a student's sex through visual inspection of such student's external sex organs for purposes of participation in competitions;

     O.C.G.A. 20-2-315(d)(6), lines 136-139
8. Government Florida Senate (bill archive). HB 1475 (2021), as filed

   Florida's 2021 House bill on girls' sports, whose dispute clause used the words I-638 later adopted.

   Reliability: Official bill text; this version did not become law.

   • Qualifies: Florida's House bill used I-638's verification words, but only to resolve a dispute about a student's sex.

     What the source says

     The health care provider may verify the student's biological sex as part of a routine sports physical examination by relying only on one or more of the following:

     Proposed s. 1006.205(3)(c), lines 59-62
9. Government Florida Legislature. Florida Statutes 1006.205, Fairness in Women's Sports Act

   The enacted Florida law.

   Reliability: Official statute text published by the Florida Legislature.

   • The enacted Florida law uses the birth certificate instead of a provider check.

     What the source says

     a statement of a student’s biological sex on the student’s official birth certificate is considered to have correctly stated the student’s biological sex at birth if the statement was filed at or near the time of the student’s birth.

     1006.205(3)(d)
10. Government Ohio General Assembly. HB 151 (134th General Assembly), as passed by the House, June 1, 2022

    Ohio House-passed bill whose girls'-sports amendment included a physician-statement dispute clause later removed in the Senate.

    Reliability: Official bill text; this provision was not enacted.

    • Qualifies: Ohio's House-passed 2022 clause required a physician's statement based on internal and external anatomy, testosterone and genetics for any disputed student.

      What the source says

      If a participant's sex is disputed, the participant shall establish the participant's sex by presenting a signed physician's statement indicating the participant's sex based upon only the following:

      Proposed R.C. 3313.5318(C)
11. Government Supreme Court of the United States. West Virginia v. B.P.J., No. 24-43 (with Little v. Hecox, No. 24-38), opinion of June 30, 2026

    The Court's opinion upholding West Virginia's and Idaho's laws.

    Reliability: Slip opinion of the Court; decided 6-3 on equal protection.

    • The Supreme Court held that states may limit girls' sports to biological females and set eligibility by biological sex.

      What the source says

      Consistent with Title IX and the Equal Protection Clause, we hold that the States may maintain women's and girls' sports for biological females.

      Opinion of the Court, conclusion
12. Advocacy group Movement Advancement Project. Bans on transgender youth participation in sports (data as of October 22, 2026)

    A state-by-state tracker of these laws, used as a completeness check.

    Reliability: MAP is an LGBTQ-rights think tank that opposes these laws; we used only its list of states, which matches our count of 27 laws.

    • The tracker marks 27 states with this description, matching our list of state laws before Alaska's regulation is added.

      What the source says

      State law bans transgender students from participating in sports consistent with their gender identity

      State map entries (27 states)
13. Party to the dispute No Hate in WA State. About I-638

    The No campaign's explanation of its arguments.

    Reliability: Has a stake in this finding. The committee opposing I-638, which wrote the No argument in the voters' pamphlet.

    • Qualifies: The No campaign says the measure is the most extreme because it targets girls with genital exams to certify their sex and exempts boys.

      What the source says

      This is the most extreme MAGA measure of its kind in the country because it targets girls with invasive genital exams to medically certify their sex. Boys are completely exempt from this requirement

      Section headed by that sentence
14. FactHub record FactHub Research Team. State laws compared with I-638: strictness by dimension (saved analysis)

    Our count, for eight dimensions, of state measures stricter than, the same as, or looser than I-638.

    • 25 of the 28 enacted state measures also cover college sports; I-638 does not.

    • 24 of the 28 let harmed students sue (four of them only for injunctions or only at colleges); I-638 creates no right to sue.

    • Qualifies: Eight state laws start at grade 5 or later; I-638's text, like 20 others, states no grade floor.

    • Qualifies: Only Oklahoma, Utah and Nebraska require proof of sex from every athlete, and only Nebraska requires a doctor's signature; none limits a routine check to anatomy, genetics or testosterone.

15. FactHub record FactHub Research Team. How state K-12 laws determine sex (saved analysis)

    Our count of state measures by verification method.

    • Qualifies: 14 state laws state no method, 11 use the birth certificate, and one each use a parent affidavit (Oklahoma), a doctor-signed document for all athletes (Nebraska), and a provider statement on dispute (Idaho).

16. Government Washington State Legislature (Washington Administrative Code). WAC 246-490-075, Changing sex designation on a birth certificate (WSR 18-02-048, effective January 27, 2018)

    The Department of Health rule that lets the sex designation on a Washington birth certificate be changed.

    Reliability: The official text of a Department of Health rule, as published in the Washington Administrative Code.

    • Qualifies: A parent or legal guardian may apply to change the sex designation on a minor's Washington birth certificate.

      What the source says

      Only the parent or legal guardian of a minor may apply to change sex designation on the minor's birth certificate.

      WAC 246-490-075(3)

    • Qualifies: For a minor, a licensed provider attests that the change is consistent with the minor's identity, so a Washington certificate need not reflect biological sex.

      What the source says

      The sex designation change application of a minor must include a signed statement by the minor's licensed health care provider attesting that: (a) The minor identified on the application is under the care of the provider; and (b) The provider has determined the request to change sex designation on the birth certificate is consistent with the minor's identity.

      WAC 246-490-075(7)
17. FactHub dataset Initiative 638: the campaigns' claims in their own words

    • Vote No Because It's the Most Extreme Proposal of Its Kind In The U.S

      Committee for the argument against Initiative IL26-638 (Justin Gill, APRN, and five co-authors), Authors of the official voters' pamphlet argument against IL26-638, September 17, 2026 · In the dataset

    • These requirements apply to girls only, boys are exempt.

      Committee for the argument against Initiative IL26-638 (Justin Gill, APRN, and five co-authors), Authors of the official voters' pamphlet argument against IL26-638, September 17, 2026 · In the dataset
18. FactHub dataset State laws on girls' school sports eligibility, compared with Washington's I-638

    Tables: state-laws

    Saved analysis strictness-vs-i638; table state-laws

19. FactHub chart i638-vs-state-laws-by-dimension

Update history

1. October 23, 2026 First version.
2. October 23, 2026 Version 2. Added Washington's rule (WAC 246-490-075, effective 2018) letting the sex designation on a birth certificate be changed, where the article compares states that rely on birth certificates: those states name the original certificate, and in Washington a birth-certificate rule would not track biological sex. Updated links to the birth-certificate and world-policies checks.
3. October 23, 2026 Updated related links to the final versions of sibling articles.
4. October 23, 2026 Said plainly in the conclusion and the birth-certificate objection that the birth-certificate comparison is not like for like: all 11 birth-certificate states specify the original certificate issued at or near birth, while a Washington certificate's sex designation can be changed (WAC 246-490-075, since 2018; M, F or X; for minors with a provider's statement). Updated related links to the final versions of sibling articles. No change to the claim or rating.