Photograph of United States Women’s Gymnasts Medalists Celebrating Victory Jordan Chiles, Hezly Rivera, Simone Biles, Jade Carey, Sunisa Lee, in Marcus Gilliar, GES-Sportfotor/Getty Images (2024).
Authored by: Reagan Keener
Little v. Hecox presented the Supreme Court with a significant question at the intersection of gender identity, athletics, and constitutional law.[1] Arising from Idaho’s Fairness in Women’s Sports Act, the case asked whether state laws that bar biological males from competing on female athletic teams are consistent with federal law. Specifically, the dispute asked whether such restrictions violate Title IX, which prohibits sex-based discrimination in federally funded education programs,[2] and/or the Equal Protection Clause, which requires states to treat similarly situated individuals alike.[3] The Court heard oral argument on January 13, 2026. On June 30, 2026, the Court, in an opinion by Justice Kavanaugh, held that Title IX and the Equal Protection Clause do not prohibit schools from determining eligibility for women’s and girls’ sports based on biological sex.[4] The Court decided Hecox together with West Virginia v. B. P. J., issuing a single opinion under the B.P.J. caption and reversing and remanding both cases.[5]
Setting the Stage: Idaho’s Fairness in Women’s Sports Act
In 2020, the Idaho Legislature passed House Bill 500, creating the Fairness in Women’s Sports Act (hereinafter “the Act”), the first law of its kind in the United States.[6] This law bans students of the male sex from participating in girls’ and women’s sports at all scholastic and collegiate levels.[7] Notably, the statute grounds eligibility in reproductive biology at birth to define sex, specifically referencing internal and external anatomy, chromosomes, and hormone profiles.[8] To enforce this, the law allows disputes over an athlete’s sex to be resolved through medical verification, which can include a physicians statement and, if challenged, more invasive evidence such as genetic testing or anatomical examination.[9] Moreover, the Act contains a legislative finding that the athletic benefit natural testosterone provides to male athletes is not diminished by puberty blockers or cross-sex hormones which was a finding the Court treated as within the legislature’s competence to make.[10]
Idaho was the first state to adopt this approach, helping to spark a similar wave of legislation across the country.[11] Lawsuits quickly followed—Idaho’s law was soon challenged in Hecox v. Little.[12] The plaintiff, Lindsay Hecox, a biological male athlete who identified as female, challenged the law as violating the Equal Protection Clause and Title IX.[13] Lower courts blocked enforcement, reasoning that Idaho had not proven the law was substantially related to promoting fairness in female sports, a standard required under intermediate scrutiny.[14]
Supporters of the Act argue it protects competitive fairness and preserves opportunities for female athletes, especially in contexts where scholarships, recruitment, and elite competition are at stake, asserting that biological differences between males and females can create inherent advantages in strength, speed, and endurance.[15] They contend that without such safeguards, female athletes may face diminished playing time, fewer opportunities for recognition, and reduced access to resources intended to support women’s sports.[16] Critics, however, counter that the Act excludes athletes who identify with a gender different from their biological one, denying them the ability to compete consistent with their gender identity, and may conflict with federal civil rights protections, including Title IX, which prohibits sex-based discrimination in education programs that receive federal funding.[17] Moreover, opponents highlight privacy concerns related to the Act’s verification procedures and question whether a blanket exclusion is narrowly tailored to achieve its stated objectives, raising both constitutional and policy debates about the appropriate balance between fairness, inclusion, and individual rights.[18] The Court ultimately adopted the supporters’ framing on both statutory and constitutional grounds, though it took care to say that no student-athlete on either side of the issue deserves to be ostracized or vilified.[19]
Equal Protection in the Courtroom
At the heart of the constitutional challenge in Little v. Hecox is the Equal Protection Clause of the Fourteenth Amendment which commands that similar individuals be treated alike under the law and forbids unjustified classifications by the state.[20] Sex‑based classifications historically have not been subject to the most rigorous form of judicial review, but they are treated as quasi‑suspect and therefore guarded by intermediate scrutiny. Under intermediate scrutiny, a law must be substantially related to an important governmental objective to be upheld. In the seminal equal protection cases addressing sex, the Supreme Court explained that discrimination on the basis of sex must be justified by an exceedingly persuasive justification and that statutory schemes reliant on broad generalizations about the abilities of males and females will not survive judicial review unless they bear substantially on the legislative purpose. This intermediate scrutiny framework is well established in equal protection jurisprudence and has been applied by multiple federal appellate courts where sex‑based distinctions are challenged.[21]
In defending Idaho’s statute, the State anchored its justification in the important government objective of preserving fair competition for biological female athletes, arguing that biological differences between males and females produce unequal athletic advantages in competitive sports.[22] Opponents countered that a categorical ban on all biological males, regardless of individual performance metrics, hormonal status, or physical characteristics, lacks the requisite substantial relation to this interest and instead rests on overbroad generalizations, raising serious equal protection concerns.[23]
The Court agreed with the States. Rejecting the plaintiffs’ as-applied theory, the Court held that States need not conduct an individual-by-individual comparison of athletic capability to satisfy intermediate scrutiny, reasoning that such athlete-by-athlete assessments are a task legislatures and schools are better equipped than courts to perform.[24] The Court further held that the laws classify on the basis of biological sex rather than transgender status, and that the classification would survive either rational basis review or intermediate scrutiny in any event.[25]
Lessons from Bostock: Can Employment Precedent Shape Sports Law?
In Bostock v. Clayton County, the Court resolved a long-standing circuit split when it held that employment discrimination against individuals based on gender identity or sexual orientation counts as sex discrimination under Title VII of the Civil Rights Act of 1964.[26] In a 6-3 decision, the Court emphasized that the interpretation of Title VII’s prohibition of employment discrimination “because of sex” protects individuals with different sexual orientations and identities.[27]
Although Bostock arose in the employment context, its textualist reasoning—namely, that discrimination on the basis of sexual orientation or gender identity necessarily entails discrimination because of sex—has reverberated far beyond workplace law. Federal agencies and lower courts have since grappled with whether the logic of Bostock should inform interpretations of other federal statutes that prohibit sex discrimination, including Title IX. Following Bostock, lower courts and federal agencies have disagreed over the extent to which its interpretation of Title VII should inform other federal statutes prohibiting sex discrimination.[28]
Despite these developments, critics caution that educational athletics and Title IX differ substantially from Title VII employment contexts in both purpose and statutory structure, leaving the Court to balance precedent with statutory text and policy concerns.[29] Whereas Title VII governs the terms and conditions of employment, Title IX’s implementing regulations expressly authorize separate teams for members of each sex.[30]
Stakes & Implications
The Court’s resolution carries consequences far beyond Idaho by providing states with a federal-law basis for maintaining sex-separated athletic teams according to biological sex rather than requiring schools to assess eligibility athlete by athlete.
The case arrived amid heightened national and international attention to the regulation of sex in sport. Athletic governing bodies, including the International Olympic Committee (“IOC”), have increasingly grappled with how to reconcile inclusion with competitive equity, adopting policies that emphasize fairness, safety, and the integrity of women’s competition. Specifically, the IOC adopted a policy in March 2026 limiting the female category in Olympic sport to biological females, finding that athletes retain male performance advantage in part through training effects and fixed traits and that no current evidence shows testosterone suppression eliminates it. The Court quoted that finding twice.[31] Against this backdrop, the Court’s decision did not occur merely in isolation but as part of a broader societal reckoning over the meaning of sex, gender identity, and equality in competitive spaces.
Ultimately, this case clarifies a vital boundary in federal anti-discrimination law concerning sex-separated athletics. The Court confirmed that Bostock does not necessarily resolve the meaning of “sex” in other federal statutes, particularly where the statutory text and regulatory structure differ from Title VII.[32] For educational institutions, the decision establishes that schools may determine eligibility for women’s and girls’ teams according to biological sex without violating Title IX or the Equal Protection Clause. The Court nevertheless expressly declined to decide the distinct question whether schools may permit biological males who identify as female to participate on women’s and girls’ teams. Thus, while the decision substantially resolves the constitutional status of categorical biological-sex eligibility rules, it leaves some questions concerning affirmative inclusion policies for future litigation.
[1] West Virginia v. B.P.J., 146 S. Ct. 2356 (2026).
[2] 20 U.S.C. § 1681(a).
[3] U.S. Const. amend. XIV, § 1.
[4] B.P.J., 146 S. Ct. at 2381
[5] Id. at 2373-75.
[6] Idaho Code Ann. § 33-6203 (2020).
[7] Id. (stating that “[t]eams designated for females . . . shall not be open to students of the male sex.”).
[8] Idaho Code Ann. § 33-6202.
[9] Id.
[10] Idaho Code Ann. § 33-6202(11) (2020).
[11] See, e.g., W. Va. Code Ann. § 18-2-25d (2022); Miss. Code Ann. § 37-97-1 (2021); Fla. Stat. § 1006.205 (2021).
[12] 479 F. Supp. 3d 930, 943-44 (D. Idaho 2020).
[13] Id.
[14] Hecox v. Little, 104 F.4th 1061 (9th Cir. 2024).
[15] B.P.J., 146 S. Ct. at 2367.
[16] Little, 104 F.4th 1061, 1077–78 (9th Cir. 2024); Brianna Herlihy, Critics Slam Federal Court for Blocking Idaho Law Barring Biological Males from Girls’ and Women’s Sports, Fox News (Aug. 17, 2023), https://www.foxnews.com/us/critics-slam-federal-court-blocking-idaho-law-barring-biological-males-from-girls-womens-sports.
[17] Karen M. Lent et al., Transgender Athlete Debate: Navigating State Bans, Equal Protection Claims and Executive Orders, Reuters (Aug. 12, 2025) https://www.reuters.com/legal/litigation/transgender-athlete-debate-navigating-state-bans-equal-protection-claims-2025-08-12/.
[18] Id.
[19] B.P.J., 146 S. Ct. at 2384.
[20] U.S. Const. amend. XIV, § 1.
[21] See, e.g., United States v. Virginia, 518 U.S. 515, 532-34 (1996) (reaffirming intermediate scrutiny for sex classifications); Craig v. Boren, 429 U.S. 190, 197-99 (1976) (establishing that sex‑based classifications are subject to intermediate scrutiny).
[22] Little, 479 F. Supp. 3d at 977.
[23] Id. at 979.
[24] B.P.J., 146 S. Ct. at 2365.
[25] Id. at 2378-79.
[26] 590 U.S. 644, 683 (2020) (holding that “[a]n employer who fires an individual merely for being gay or transgender defies the law.”).
[27] Id.
[28] Compare Grimm v. Gloucester Cnty. Sch. Bd., 972 F.3d 586, 616 (4th Cir. 2020) (finding “little difficulty” after Bostock in concluding that a school policy barring a transgender student from the corresponding restroom violated Title IX), cert. denied, 141 S. Ct. 2878 (2021), with Adams ex rel. Kasper v. Sch. Bd. of St. Johns Cnty., 57 F.4th 791, 811–15 (11th Cir. 2022) (en banc) (declining to extend Bostock to Title IX, and stressing that Bostock expressly reserved the question of sex-separated facilities and that a school is not the adult workplace).
[29] Uma Rajan, Defining “Sex” For Sports?: Legal Frameworks Under Title IX, Col. Undergrad. L. Rev. (Dec. 8, 2025), https://www.culawreview.org/current-events-2/defining-sex-for-sports-legal-frameworks-under-title-ix.
[30] 34 C.F.R. § 106.41(b) (2025); 20 U.S.C. § 1686.
[31]B.P.J., 146 S. Ct. at 2380; International Olympic Committee Announces New Policy on the Protection of the Female (Women’s) Category in Olympic Sport, Int’l Olympic Comm. (Mar. 26, 2026), https://www.olympics.com/ioc/news/international-olympic-committee-announces-new-policy-on-the-protection-of-the-female-women-s-category-in-olympic-sport.
[32] Erwin Chemerinsky, Wither Bostock?, SCOTUSBlog (Jan. 15, 2026), https://www.scotusblog.com/2026/01/whither-bostock/.