West Virginia v. B. P. J.

JUSTICE KAVANAUGH delivered the opinion of the Court. Title IX transformed American sports and American life. Enacted in 1972, that landmark law promoted equal opportunity for female student-athletes and has facilitated the extraordinary growth of women’s and girls’ sports over the past 54 years. To provide equal opportunity for female athletes, schools do not merely maintain, for example, one soccer team, one basketball team, one ice hockey team, and one lacrosse team that are equally open to female and male athletes. That approach would deny equal opportunity to female athletes because, as all ag ree, females and males have 2 WEST VIRGINIA v. B. P. J. Opinion of the Court inherent physical differenc es relevant to athletic performance. Those “[p]hysical differences between men and women” are “enduring.” United States v. Virginia, 518 U. S. 515, 533 (1996). The differences include, among other things, height, weight, strength, speed, endurance, and jumping ability. Therefore, in contact sports, forcing female athletes to compete against males can create significant safety risks. And in virtually all competitive sports, forcing female athletes to compete against males can undermine competitive fairness. To ensure equal opportunity for female athletes, schools therefore typically maintain separate women’s and men’s sports teams. Women’s teams compete against other women’s teams, and men’s teams compete against other men’s teams. To ensure equal opportunity, Title IX’s regulations also require schools to provide the women’s and men’s teams equivalent equipment, facilities, scheduling, and the like. In recent years, some biological males who identify as female have sought to play on women’s or girls’ sports teams. That modern deve lopment has triggered national and international concerns about safety and competitive fairness for female athletes, as well as related worries about preserving equal opportunity for women and girls to play sports. For those reasons, 27 States—as well as the International Olympic Committee, the United States Olympic and Paralympic Committee, and the NCAA—have banned all biological males from competing in women’s and girls’ sports. These cases concern two of those state laws, from West Virginia and Idaho. The question before the Court is: Under Title IX and the Equal Protection Clause of the Fourteenth Amendment, may schools maintain women’s and girls’ sports for biological females? In other words, may 3 Cite as: 609 U. S. ____ (2026) Opinion of the Court schools determine eligibility for women’s and girls’ sports based on biological sex? The answer is yes.1 I A Prior to Title IX’s enactment in 1972, the participation of the two sexes in American sports was badly skewed. In the 1971–1972 school year, only about 300,000 high school girls played sports. Meanwhile, about 3.6 million high school boys played sports. The situation was similarly imbalanced at the college level. See NCAA, Title IX 50th Anniversary: The State of Women in College Sports 15, 17. The low female participation rate was the byproduct of overt sex discrimination, as well as mistaken stereotyping of American women and girls. Men and boys usually received more encouragement and more opportunities to play sports than women and girls. And male sports teams typically received more funding and resources than female teams. As of 1972, for exampl e, women’s sports reportedly accounted for only 2% of annual college athletics spending. 130 Cong. Rec. S4601 (Apr. 12, 1984) (remarks of Sen. Stevens). In 1972, in a belated but historic response to persistent discrimination against women in educational institutions, including in athletics, Congress passed and President Nixon signed Title IX of the Education Amendments of 1972. Title IX prohibits “discrimination under any —————— 1 As the plaintiffs, the States, and the United States as amicus curiae all agree, these cases do not present the distinct question of whether, under Title IX and the Equal Pr otection Clause, schools may allow biological males who identify as fe male to participate on girls’ and women’s sports teams. That question is currently the subject of litigation in some lower courts. Nothing in this opinion is intended to decide that question. In addition, nothing in th is opinion should be interpreted to address or limit participation by biological females on male or co-ed sports teams. 4 WEST VIRGINIA v. B. P. J. Opinion of the Court education program or activity receiving Federal financial assistance” “on the basis of sex.” 20 U. S. C. §1681(a). Few laws have been as effective and consequential in day- to-day American life as Title IX. Every day across America, gyms, fields, and other sports venues are filled with female athletes competing fiercely in youth, high school, college, and professional sports. About 3.5 million high school girls now play sports. Nat. Federation of State High School Assns., 2024–2025 High School Athletics Participation Survey, p. 57 (Aug. 22, 2025). An additional 235,000 women play competitively in college. NCAA, Title IX 50th Anniversary: The State of Women in College Sports 16–17; NCAA, Sports Sponsorship and Participation Rates Report, p. 94 (Sept. 4, 2025). Participation in sports has enabled countless American women and girls to be on a team, to take part in the human drama of athletic competition, to overcome the agony of defeat and know the thrill of victory. And those lessons and experiences in sports have empowered millions of American women who have gone on to thrive in all aspects of American life. B Over the past several years, some biological males who identify as female have sought to play various women’s and girls’ sports. Some of them have taken, as relevant here: (i) puberty-blocking drugs that suppress the rise of puberty- inducing hormones; or (ii) cross-sex hormones and other drugs, such as those that suppress testosterone or increase estrogen, sometimes called hormone therapy. (For ease of reference, we will refer to puberty blockers and hormones.) Those biological males conten d that by taking puberty blockers or hormones, they can mitigate the physical advantages inherent to their bi ological sex, as relevant to sports. 5 Cite as: 609 U. S. ____ (2026) Opinion of the Court Intense policy and legal disputes have ensued over whether biological males should be allowed to play on women’s and girls’ sports teams. Many athletic organizations and States have recently acted decisively to prohibit all biological males from participating in women’s sports—that is, to limit women’s and girls’ teams to biological females. In 2025, the NCAA prohibited biological male students, including those who identify as female and have taken hormones, from competing on women’s teams. The U. S. Olympic and Paralympic Committee followed suit, likewise prohibiting biological males from competing in women’s sports. NCAA, Participation Policy for Transgender Student-Athletes (Feb. 6, 2025); USOPC, Athlete Safety Policy §3.3 (June 18, 2025). More recently, the International Olympic Committee similarly limited Olympic parti cipation in women’s sports to biological females. The IO C did so in order to “protect fairness in such sports and events, as well as safety particularly in contact sports.” The IOC found that biological males possess a “performance advantage in all sports and events that rely on strength, power, and/or endurance,” including a “20+ per cent” advantage in “most throwing and jumping events,” a “10-12 per cent” advantage in “most running and swimming events,” and a “greater than 100 per cent” advantage in “events that involve explosive power.” IOC, Policy on the Protection of the Female (Women’s) Category in Olympic Sport and Guiding Considerations for International Federations and Sports Governing Bodies 2, 3 (Mar. 26, 2026). Moreover, the IOC found that “athletes retain Male performance advantage due in part to training effects and fixed traits. There is no current evidence that testosterone suppression or gender-affirming hormone treatment eliminates this advantage.” Id., at 3. 6 WEST VIRGINIA v. B. P. J. Opinion of the Court Most relevant for present purposes: In the past six years, 27 States have enacted laws that maintain women’s and girls’ sports for biological females. These cases concern two of those state laws, from West Virginia and Idaho. C West Virginia has long authorized sex-separated school sports teams “where selection for such teams is based upon competitive skill.” W. Va. Code Rule §127–2–3.8 (2025). In 2021, the West Virginia Legislature passed and Governor Justice signed the Save Women’s Sports Act. The Save Women’s Sports Act prohibits male students from playing on female teams. W. Va. Code Ann. §§18–2–25d(c)(2)–(3) (2022). The law specifies that sex is determined by biology. §§18–2–25d(a)(4), (b)(1). The legislature expressly found that prohibiting biological male participation in female sports is necessary to promote equal athletic opportunities for women and girls. See §§18–2–25d(a)(1), (3), (5). B. P. J. is a biological male who identifies as female. In third grade, B. P. J. socially transitioned and adopted a new name. Soon thereafter, B. P. J. took puberty blockers to prevent male puberty, and in sixth grade, B. P. J. also began to take hormones. Shortly after passage of the West Virginia law, as B. P. J. was about to enter sixth grade, B. P. J.’s middle school principal informed B. P. J.’s mother that B. P. J. could not participate on the girls’ cross-country and track-and-field teams. B. P. J. is now in high school, where the same policies apply. B. P. J. sued West Virginia officials and agencies for alleged violations of Title IX and the Equal Protection Clause of the Fourteenth Amendment. The U. S. District Court for the Southern District of West Virginia granted summary judgment for the State on both claims. On appeal, the U. S. Court of Appeals for the Fourth Circuit 7 Cite as: 609 U. S. ____ (2026) Opinion of the Court reversed on the Title IX issue and remanded for further fact-finding on the Equal Protection Clause claim. 98 F. 4th 542 (2024). This Court granted certiorari. 606 U. S. 959 (2025). During the ongoing litigation, B. P. J. competed on the teams. Recently, B. P. J. won the West Virginia Class AAA high school state championship in girls’ shot put and finished fourth in girls’ discus. B. P. J. won the Region 2 championship in both events. See Supp. Letter of W. Va. in No. 24–43 (May 29, 2026). D In 2020, the Idaho Legislature passed and Governor Little signed the Fairness in Women’s Sports Act. Like the West Virginia law, the Idaho law prohibits male students from participating on female teams. Idaho Code Ann. §33– 6203. The Idaho law states that sex is determined by biology. Ibid. And the law declares that “separate sex-specific teams furthers efforts to promote sex equality . . . by providing opportunities for female athletes.” §33–6202(12) (2025). It also recognizes the ph ysical differences between biological males and biological females. §§33–6202(1)–(5), (7), (8), (10)–(12). The law further found that the benefit “that natural testosterone provides to male athletes is not diminished through the use of puberty blockers and cross-sex hormones. §33–6202(11). Hecox is a biological male who identifies as female. Hecox underwent male puberty. In college, Hecox began to take hormones. Hecox attends Boise State University and has competed for the women’s club soccer team. Hecox also has tried out for the women’s Division I track and cross- country teams. Shortly after Idaho enacted the Fairness in Women’s Sports Act, Hecox sued Idaho officials and agencies, 8 WEST VIRGINIA v. B. P. J. Opinion of the Court alleging a violation of the Equal Protection Clause. The U. S. District Court for the District of Idaho granted a preliminary injunction barring enforcement of the Fairness in Women’s Sports Act, and the U. S. Court of Appeals for the Ninth Circuit affirmed. 104 F. 4th 1061 (2023). This Court granted certiorari. 606 U. S. 959 (2025). II We first address the Title IX issue, which is raised only by B. P. J. in the West Virginia case. B. P. J. argues that the State and school officials violated Title IX by excluding B. P. J. from the girls’ cross-country and track-and-field teams. Under Title IX, according to B. P. J., schools must allow biological males who identify as female and have taken puberty blockers or hormones to compete on girls’ sports teams. We respectfully disagree. A Passed by Congress and signed by President Nixon in 1972, Title IX provides: “No person in the United States shall, on the basis of sex, be excluded from participation in, be denied the benefits of, or be subjected to discrimination under any education program or activity receiving Federal financial assistance.” 20 U. S. C. §1681(a). As originally enacted, Title IX did not explicitly address sports. Two years after Title IX became law, Congress passed and President Ford signed what is known as the Javits Amendment. The Javits Amendment directed the then-Department of Health, Education, and Welfare (HEW) to promptly issue “regulations implementing the provisions of ” Title IX with respect to “the prohibition of sex discrimination.” §844, 88 Stat. 612. The amendment further specified that the regulations “shall include with respect to” “athletic activities reasonable provisions considering the nature of particular sports .” Ibid. (emphasis added). 9 Cite as: 609 U. S. ____ (2026) Opinion of the Court In 1975, pursuant to that statutory directive, HEW promulgated comprehensive regulations to prevent sex discrimination in school sports. 40 Fed. Reg. 24128. Most critically, the regulations required that schools provide “equal athletic opportunity for members of both sexes” and authorized “separate teams for members of each sex where selection for such teams is bas ed upon competitive skill or the activity involved is a contact sport.” 34 CFR §§106.41(b), (c) (2025). The regulations defined contact sports as “boxing, wrestling, rugby, ice hockey, football, basketball and other sports the purpose or major activity of which involves bodily contact.” Ibid. Those regulations took effect on July 21, 1975, and they remain in place today. Because HEW’s interpretation of Title IX was “issued contemporaneously with the statute” and has “remained consistent over time,” it is “especially useful in determining the statute’s meaning.” Loper Bright Enterprises v. Raimondo, 603 U. S. 369, 394 (2024). 2 B The question is whether Title IX permits schools to maintain women’s and girls’ sports for biological females. The answer is yes. Title IX prohibits discrimination on the basis of sex. Title IX’s implementing regulations expressly permit schools to maintain separate teams for “members of each sex.” —————— 2 In relevant part, §106.41 of the regulations states: “(b) Separate teams. Notwithstanding the re quirements of paragraph (a) of this section, a recipient may operate or sponsor separate teams for members of each sex where selection for such teams is based upon competitive skill or the acti vity involved is a contact sport. . . . For the purposes of this part, contact sports include boxing, wrestling, rugby, ice hockey, football, basketball and ot her sports the purpose or major activity of which involves bodily contact. “(c) Equal opportunity . A recipient which operates or sponsors interscholastic, intercollegiate, club or intramural athletics shall provide equal athletic opportunity for members of both sexes.” 10 WEST VIRGINIA v. B. P. J. Opinion of the Court §106.41(b). The term “sex” in the 1972 Title IX statute, the 1974 Javits Amendment, and the 1975 Title IX regulations cannot plausibly be interprete d to refer to anything other than biological sex. The ordinary meaning of the term “sex” at the time of enactment in the early 1970s was biological sex and not gender identity, particularly in the sports context. See, e.g., Frontiero v. Richardson , 411 U. S. 677, 686 (1973) (plurality opinion) (“sex” is “an immutable characteristic”). In addition, the Title IX regulations allowed separate sports teams precisely because of the biological differences between the sexes—namely, the inherent physical differences between biological women and biological men. For example, the regulations authorized separate women’s and girls’ teams in sports when the teams are “based upon competitive skill or the activity involved is a contact sport.” §106.41(b). By referring to co ntact sports and competitive skill, the regulations plainly recognized the inherent physical differences between biological men and biological women—as well as the safety and competitive fairness concerns that would arise if males were allowed to compete in female sports. As Justice Stevens explained a few years afterwards: “Without a gender-based classification in competitive contact sports, there would be a substantial risk that boys would dominate the girls’ programs and deny them an equal opportunity to compete in interscholastic events.” O’Connor v. Board of Ed. of School Dist. 23 , 449 U. S. 1301, 1307 (1980) (in chambers). Notably, B. P. J. does not seriously contest that the term “sex” in Title IX, the Javits Amendment, and the regulations means biological sex. Moreover, B. P. J. agrees with West Virginia and the United States as amicus curiae that Title IX permits schools to maintain separate female and male teams and to prohibit most biological males from playing on women’s and girls’ teams. B. P. J. disagrees with West Virginia and the United States only about 11 Cite as: 609 U. S. ____ (2026) Opinion of the Court whether schools must make an exception to that general rule for biological males who identify as female and have taken puberty blockers or hormones. But the texts of Title IX, the Javits Amendment, and the Title IX regulations do not say (or even hint) that schools must allow certain biological males to participate in women’s and girls’ sports. Nor do the statute or regulations say that schools must make an exception for those biological males who identify as female and have taken puberty blockers or hormones. Put simply, the statute and regulations do not speak to that issue in a way that could properly be interpreted to require schools to allow biological males to participate in women’s and girls’ sports. B. P. J. counters with an argument based on the 1974 Javits Amendment. B. P. J. zeroes in on the Javits Amendment’s directive that HEW, in its regulations, adopt “reasonable provisions considering the nature of particular sports.” §844, 88 Stat. 612 (emphasis added). As B. P. J. sees things, if the regulation s authorize a school to limit women’s and girls’ sports teams to biological females, then the regulations are not “reasonable” and therefore are unlawful. We disagree. Separate sports teams for biological males and biological females are reasonable: Given the inherent physical differences between the sexes, allowing only biological females to play on women’s and girls’ teams can reduce the risk of physical injury and ensure fair competition. True, some might prefer a different rule allowing biological males who identify as female to participate on women’s and girls’ sports teams, at least in certain circumstances. But it was surely “reasonable” for HEW in 1975 to draw a biological line—a line where biological males play only on male sports teams and only biological females play on female sports teams. Even in recent years, 27 States, the NCAA, the USOPC, and the IOC have all drawn the same line. 12 WEST VIRGINIA v. B. P. J. Opinion of the Court In assessing the reasonableness of the regulations, we also must recognize the distinctiveness of competitive sports—and the safety and competitive fairness issues that can arise when females are forced to compete against males. With respect to safety, allowi ng biological males to play on women’s and girls’ sports teams can put women and girls at significant risk of injuries. The safety risks are particularly severe in contact sports. And as to competitive fairness, allowing biological males to play on women’s and girls’ sports teams can put female athletes at a serious disadvantag e. That is because sports are generally zero sum. Allowi ng a biological male athlete to compete on a girls’ team necessarily displaces or disadvantages a female athlete—replacing her on the roster, knocking her out of the starting lineup, reducing her playing time, depriving her of a medal, and the like. That hard reality of sports cannot be ignored or swept under the rug. On the contrary, that reality must and does inform interpretation of the term “reasonable” in the Javits Amendment. Whether biological males may participate on women’s and girls’ sports teams may be a debated policy question. But the legal question for Title IX purposes is whether West Virginia may limit women’s and girls’ sports teams to biological females. As a matter of text and history, West Virginia may do so. C B. P. J. advances two other Title IX-related arguments that warrant brief mention. First, B. P. J. contends that the school’s policy violates Title IX because the policy effectively excludes B. P. J. from any competitive sports teams at the school. B. P. J. has taken puberty blockers and hormones, meaning that B. P. J. apparently will no longer be strong or fast enough 13 Cite as: 609 U. S. ____ (2026) Opinion of the Court to compete successfully against boys. Moreover, B. P. J. might not want to compete against boys. Either way, it is an unhappy occasion whenever a student who wants to play school sports cannot do so. We appreciate the desire of every student, including B. P. J., who wants to play school sports. And we recognize that student-athletes are understandably disappointed and upset when they do not make a team or otherwise cannot participate. But the Title IX regulations guarantee “equal athletic opportunity.” The regulations cannot and do not guarantee every student a spot on a team’s roster. Second, B. P. J. cites Title VII of the Civil Rights Act of 1964, 42 U. S. C. §2000e–2(a)(1), and Bostock as support for interpreting Title IX to require that schools allow biological males on female teams. Title VII prohibits employment discrimination “because of . . . sex,” and Bostock held that the prohibition forbids firing an employee “for being gay or transgender.” Bostock v. Clayton County , 590 U. S. 644, 662 (2020). B. P. J. contends that Title IX similarly bars West Virginia’s law because (as B. P. J. sees things) the law excludes B. P. J. from sports on the basis of gender identity. We disagree. Title VII concerns employment, whereas Title IX as relevant here focuses on sports. The two factual contexts are vastly different. And the two statutes are also “vastly different.” Jackson v. Birmingham Bd. of Ed. , 544 U. S. 167, 175 (2005). In the workplace, Title VII generally requires that men and women be treated without regard to their sex. In the sports context, by contrast, Title IX authorizes separate men’s and women’s sports teams. And because Title IX permits separate teams, the only question here is whether schools may limit women’s and girls’ sports to biological females—a question that was not addressed by Bostock, as the Court expressly noted. See 590 U. S., at 681 (we “do not purport to address bathrooms, locker rooms, or anything else of the kind”). Stated simply, Title VII and 14 WEST VIRGINIA v. B. P. J. Opinion of the Court Bostock are not relevant in this very different statutory and factual context. In sum, Title IX allows schools to provide separate women’s and men’s sports teams defined by biological sex. Consistent with Title IX, West Virginia has permissibly maintained women’s and girls’ sports for biological females. III We next address the constitutional challenges to the West Virginia and Idaho laws under the Equal Protection Clause of the Fourteenth Amendment. Both B. P. J. and Hecox raise an equal protection argument. They contend that the States violated the Equal Protection Clause by maintaining female sports teams for biological females. Again, we respectfully disagree. 3 —————— 3 After this Court granted review, Hecox filed a suggestion of mootness stating that Hecox will “cease play ing women’s sports in any context covered by” the Idaho law. App. to Suggestion of Mootness, Decl. of L. Hecox in No. 24–38, ¶6 (Sept. 1, 2025). As the party asserting mootness, Hecox bears the “formidable burden of showing that it is absolutely clear the . . . behavior could not reasonably be expected to recur.” Already, LLC v. Nike, Inc., 568 U. S. 85, 91 (2013) (quotation marks omitted). Hecox has been a student at Boise State University since 2019 and is still enrolled there. At Boise State, Hecox has competed on the women’s club soccer team and has sought to try out for the Division I women’s track and cross-country teams. In 2022, Hecox stated in a declaration to the Court of Appeals: “I intend to play for the BSU’s Women’s Club Soccer Team this semester, next semester, and through the remainder of my time at BSU.” Decl. of L. Hecox in No. 20–35813 etc., ¶21 (CA9, Sept. 21, 2022) (emphasis added). Only in September 2025, after this Court granted certiorari, did Hecox articulate a different view about playing competitive sports at Boise State. But that shift may not be pe rmanent, particularly given Hecox’s prior change in position. Cf. Erie v. Pap’s A. M., 529 U. S. 277, 287–288 (2000). Moreover, post-certiorari actions that would “insulate a decision from review by this Court must be viewed with a critical eye.” Knox v. Service Employees, 567 U. S. 298, 307 (2012). Hecox remains an enrolled student at Boise State. Hecox’s case is not moot. 15 Cite as: 609 U. S. ____ (2026) Opinion of the Court A Ratified in 1868, the Equal Protection Clause provides that no State shall deny “to any person within its jurisdiction the equal protection of the laws.” U. S. Const., Amdt. 14. That command “must coexist with the practical necessity that most legislation classifies for one purpose or another, with resulting disadvantage to various groups or persons.” United States v. Skrmetti, 605 U. S. 495, 509 (2025) (quotation marks omitted). Under this Court’s equal protection precedents, laws that classify by sex are subject to what is known as intermediate scrutiny: Sex-based classifications are permissible only when the classification is “substantially related” to achieving an “important” government objective. Id., at 510 (quotation marks omitted); see also United States v. Virginia, 518 U. S. 515, 532–533 (1996) (Ginsburg, J., for the Court); Mississippi Univ. for Women v. Hogan, 458 U. S. 718, 724–725 (1982) (O’Connor, J., for the Court). The West Virginia and Idaho laws authorize separate female and male sports teams. And the laws limit women’s and girls’ sports teams to biological females. In doing so, the laws make a sex-based classification that triggers intermediate scrutiny. So the equal protection questions become: What are the States’ interests in maintaining separate teams for males and females, and in limiting female teams to biological females? And is the States’ sex-based classification—that is, the limitation of women’s and girls’ sports teams to biological females—substantially related to those interests? The States start with the undisputed proposition that biological males generally possess inherent physical advantages in sports—in heig ht, weight, strength, speed, endurance, jumping ability, and the like. See United States v. Virginia, 518 U. S., at 533 (“Physical differences between men and women . . . are enduring”). Therefore, the States say, limiting women’s and girls’ sports to biological females 16 WEST VIRGINIA v. B. P. J. Opinion of the Court (i) helps prevent serious physical injuries to female athletes and (ii) preserves opportunities for female athletes to fairly compete and succeed. And more broadly, the States articulate the objective of promoting “equal athletic opportunities for the female sex”—that is, to provide opportunities for biological women and girls to compete only against other biological women and girls. W. Va. Code Ann. §18–2–25d(a)(5); see also Idaho Code Ann. §33–6202(12) (“Having separate sex-specific teams furthers efforts to promote sex equality” “by providing opportunities for female athletes to demonstrate their skill, strength, and athletic abilities”). With respect to safety, the States say that allowing biological males to play on women’s sports teams puts women and girls at significant risk of sometimes severe injuries. The safety risks are at their apex in contact sports, such as soccer, basketball, field hockey, lacrosse, and ice hockey, among others. (Anyone who thinks that those women’s and girls’ sports, and other sports like them, are not contact sports has not witnessed a game recently.) And safety concerns also exist in ostensibly non-contact sports, such as volleyball, where spiked balls can cause serious injuries, and softball, where line drives can similarly cause significant harm. As to competitive fairness, the States contend that allowing biological males to play women’s and girls’ sports would put female athletes at a debilitating disadvantage. Again, sports are generally zero sum. Every biological male who makes the team takes a roster spot from a female athlete. Every biological male who earns playing time reduces the playing time of a female athlete. Every biological male who starts takes a starting position from a female athlete. Every biological male who wins a race takes the gold medal away from a female athlete. And so on. Even if only one or a few males were to play on a women’s 17 Cite as: 609 U. S. ____ (2026) Opinion of the Court or girls’ team, that would still place specific individual female athletes at a significant competitive disadvantage. What is more, forcing women and girls to play against biological males can deter some women and girls who would otherwise participate in sports from doing so—out of understandable concern about suffering serious injury or participating in what they view as an unfair competition. That second-order effect of allowing biological males to play women’s and girls’ sports c annot be papered over, so the States say. Based on all of the above, the States argue—and we agree—that the interests in safety and competitive fairness are important for purposes of equal protection analysis. And the States’ sex-based classification—limiting women’s and girls’ sports to biologic al females—is substantially related to those interests. See Skrmetti, 605 U. S., at 510; Tuan Anh Nguyen v. INS, 533 U. S. 53, 70 (2001); Michael M. v. Superior Court, Sonoma Cty., 450 U. S. 464, 472–473 (1981) (plurality opinion). Therefore, schools may maintain women’s and girls’ sports for bi ological females. In other words, schools may determine eligibility for women’s and girls’ sports based on biological sex. B Once again, the plaintiffs agree with the States that, consistent with the Equal Protection Clause, the States may prohibit most biological males from women’s and girls’ teams. The plaintiffs’ equal protection argument is narrower. They contend that safety and competitive fairness, while sufficient reasons to exclude most biological males, do not justify excluding a relatively small subclass of biological males—namely, those biological males who identify as female and have taken puberty blockers or hormones. The plaintiffs characterize their equal protection argument in three overlapping ways—(i) as a lack of 18 WEST VIRGINIA v. B. P. J. Opinion of the Court substantial relationship between the law’s biological-sex classification and the State’s interests in safety and competitive fairness; (ii) as an as-applied challenge to the biological-sex classification; and (iii) as discrimination against transgender athletes. Under this Court’s precedents, none of those three arguments succeeds. First, the plaintiffs argue that the States have not established a substantial relationship between (i) the States’ interests in safety and competitive fairness and (ii) limiting women’s and girls’ sports to biological females. They say that the States’ interests in safety and competitive fairness do not justify excluding all biological males— including those who identify as female and have taken puberty blockers or hormones—from participation in women’s and girls’ sports. But this Court’s equal protection precedents allow general classifications like those made in the West Virginia and Idaho laws so long as there is at least a substantial relationship between the classification and the State’s interests. See United States v. Virginia, 518 U. S., at 533. After all, “most legislation cl assifies for one purpose or another, with resulting disadvantage to various groups or persons.” Skrmetti, 605 U. S., at 509 (quotation marks omitted). As the Court has long recognized, “[p]erfection in making the necessary classifications is neither possible nor necessary.” Massachusetts Bd. of Retirement v. Murgia , 427 U. S. 307, 314 (1976) ( per curiam ). For that reason, none of this Court’s “gender-based classification equal protection cases have required that the statute under consideration must be capable of achieving its ultimate objective in every instance.” Nguyen, 533 U. S., at 70. Rather, under the intermediate scrutiny test that the Court applies in a variety of contexts, the “validity of the regulation depends on the relation it bears to the overall problem the government seeks to correct, not on the extent to which it furthers the government’s interests in an 19 Cite as: 609 U. S. ____ (2026) Opinion of the Court individual case.” Ward v. Rock Against Racism , 491 U. S. 781, 801 (1989). So we “judge the validity of the restriction in this case by the relation it bears to the general problem . . . not by the extent to which it furthers the Government’s interest in an individual case.” United States v. Edge Broadcasting Co., 509 U. S. 418, 430–431 (1993). Here, when analyzing the relationship between the classification based on biological sex and the asserted interests, the sports context is again crucial. Sports are different from, say, a typica l employment or educational opportunity where equal protection often may require that the government generally treat an individual without regard to the individual’s sex. In the sports context, by contrast, everyone agrees that the States may maintain separate women’s and men’s teams—in other words, that the States may make distinctions based on sex—because of the inherent physical differences between women and men. And importantly, everyone also agrees that States, in preserving separate sports teams for female athletes, need not account for the individual physical capabilities of (and differences among) every biological male who might want to play on a women’s or girls’ team. To spell that out: Not every biological male athlete is bigger, stronger, faster, or otherwise more athletically able than every biological female athlete. Some percentage of biological males who identify as male possess physical and athletic capabilities that fall within (or below) the range of typical female physical and athletic capabilities. But the plaintiffs acknowledge that States may still exclude those biological males from women’s and girls’ sports, given the general physical differences between males and females. 4 —————— 4 That concession reveals that the plaintiffs’ argument is based not on physical capabilities alone but also on gender identity. Suppose, for example, that two boys want to play on a girls’ team. One boy identifies as male, and the other identifies as female. And suppose that both have 20 WEST VIRGINIA v. B. P. J. Opinion of the Court And the Equal Protection Clause does not prohibit the States from applying that same principle to all biological males, including those who identify as female. In the distinctive sports context, in other words, the States may treat all biological males the same and treat all biological females the same, given the inherent physical differences between biological males and biological females. In short, States are not required to conduct an individual- by-individual comparison of the physical and athletic capabilities of all biological males in order to satisfy intermediate scrutiny. Intermediate scrutiny permits a sex-based classification that, as here, is “not invidious, but rather realistically reflects the fact that the sexes are not similarly situated in certain circumstances.” Michael M., 450 U. S., at 469 (plurality opinion). Second, and relatedly, the plaintiffs advance what they describe as an as-applied equal protection argument. The plaintiffs say that the States’ sex-based classification is generally permissible—but not as applied to those biological males such as B. P. J. and Hecox who identify as female and have taken puberty blockers or hormones. But that argument is basically the same as the plaintiffs’ first argument about the relationship between the laws’ classification and the States’ interests—just with different labeling. The plaintiffs’ as-applied argument posits that the States’ interests must justify the laws’ application to a —————— the same size, height, strength, speed, jumping ability, and the like. The plaintiffs say that schools must allo w the biological male who identifies as female to play on a girls’ team. But schools may exclude from the girls’ team the biological male who identifies as male, even if he has the same physical capabilities. So the plaint iffs’ position is based not only on physical capabilities but also in part on gender identity. In a cryptic footnote, the dissent articulates the sa me view as the plaintiffs on that point. Post, at 23, n. 9 (S OTOMAYOR, J., concurring in judgment in part and dissenting in part). But the Constitution does not require that schools determine eligibility for wo men’s and girls’ sports based on gender identity rather than biological sex.   21 Cite as: 609 U. S. ____ (2026) Opinion of the Court specific subclass or individual. To be sure, the plaintiffs’ as- applied nomenclature and focus on subclasses is a useful construct in equal protection cases to help analyze the relationship between a State’s classification and the State’s asserted interests. Specifically , if a State’s interests do not apply to an especially large subclass within the class specified by the State’s law, then that fact may demonstrate that the relationship between the State’s classification and the State’s interests is not close enough. But as long as the relationship is sufficient as a general matter, the State is not constitutionally required to grant individualized exemptions to specific athletes or subclasses. 5 The plaintiffs’ as-applied argument is in essence a backdoor argument for strict scrutiny, which requires a much tighter relationship between the State’s classification and the State’s asserted interests. But strict scrutiny does not apply to sex-based classifications, as the plaintiffs acknowledge. And strict scruti ny would be particularly out of place in this sports case, where sex-based classifications are permitted and the only question is whether the States may limit women’s and girls’ sports to biological females. Especially in the sports co ntext, moreover, an enormous practical and administrability problem would arise if courts —————— 5 For support of their as-applied argument, the plaintiffs cite Caban v. Mohammed, 441 U. S. 380 (1979), and Lehr v. Robertson, 463 U. S. 248 (1983). But Caban nowhere stated that a plaintiff may obtain an as- applied exception to a law’s classification under intermediate scrutiny review. Rather, Caban looked to the facts of the case at hand to illustrate the overbroad classification. 441 U. S., at 391. And Lehr in turn rejected an asserted as-applied exception. 463 U. S., at 267–268. It is true that Lehr somewhat confusingly characterized Caban as accepting something akin to an as-applied argument. Id., at 267. But that characterization was incorrect, in our view, and in any event, Lehr’s holding did not turn on its characterization of Caban. Also, the Court’s more recent decision in Nguyen clarified that as-applied challenges are not entertained when courts apply intermediate scrutiny or rational basis review. See Tuan Anh Nguyen v. INS, 533 U. S. 53, 70 (2001). 22 WEST VIRGINIA v. B. P. J. Opinion of the Court suddenly had to make such individualized exemptions. How would courts draw those lines? Individuals come in all shapes and sizes, with different height, weight, muscle mass, heart capacity, lung capacity, strength, speed, endurance, jumping ability, and so on. Particularly in the sports context, determining the effects of the puberty blockers and hormones taken by transgender athletes—and then comparing each of those transgender athletes’ abilities to those of other individual biological males and individual biological females in the relevant sport—would be an almost impossible task for a judge to perform on an equitable basis. The legislatures and the schools are better equipped—and under the Constitution, are the more appropriate entities—to assess the competing medical and scientific considerations and draw appropriate lines. Of course, no line that the States draw will satisfy everyone. But the Judiciary is not the proper institution to make what would often be arbitrary and highly intrusive athlete-by- athlete assessments. And if those kinds of ad hoc exemptions based on physical capacity were constitutionally required, would exemptions also be required for biological males who still identify as male but contend that they, too, are no taller, no stronger, no faster than the typical females in their chosen sport? Would those males also be entitled to play on a women’s or girls’ team? If not, why not? We need not belabor the point. In the sports context, starting down the road of judicially managed individualized exemptions based on physical capabilities of individual athletes could fundamentally undermine women’s and girls’ sports—especially if the number of biological males who seek to play women’s and girls’ sports increases significantly over time. The questions would be endless (and bitter) and yield few, if any, principled answers. The Equal Protection Clause and this Court’s precedents do not require such a judicial quagmire. 23 Cite as: 609 U. S. ____ (2026) Opinion of the Court Third, the plaintiffs also argue that the States’ laws unconstitutionally discriminate against transgender individuals—specifically, biological males who identify as female. That argument, too, is unavailing. To begin, under this Court’s decision in Skrmetti, the laws do not classify based on gender identity or transgender status. 605 U. S., at 517. The laws classify on the basis of biological sex. By contrast, if a school had a co-ed sports team but prohibited all transgender individuals from participating on the team, that would be a distinct transgender classification and, unlike today’s cases, would presumably not be analyzed and justified as a classification based on biological sex. That said, even if the laws made a transgender or gender- identity classification, this Court “has not previously held” that intermediate or other heightened scrutiny applies to a transgender or gender-identity classification. Ibid. Several Members of this Court, moreover, have concluded that classifications based on transgender status or gender identity should receive only deferential rational basis review and not intermediate or other heightened scrutiny. See id., at 550–553 (B ARRETT, J., joined by T HOMAS, J., concurring); id., at 566 (A LITO, J., concurring in part and concurring in judgment). In these cases, we need not definitively resolve whether rational basis review or inte rmediate scrutiny applies to transgender classifications. In either event, the classification here readily satisfies rational basis review or intermediate scrutiny for the reasons already explained at some length above. The States’ interests in ensuring safety and competitive fairness amply justify the States in maintaining women’s and girls’ sports for biological females. Under the Equal Protection Clause, therefore, schools may determine eligibility for women’s and girls’ sports based on biological sex. 24 WEST VIRGINIA v. B. P. J. Opinion of the Court C Finally, the underlying medical and scientific premise of the plaintiffs’ entire equal protection argument is that at least some biological males who identify as female and take puberty blockers or hormones do not retain physical advantages over biological females. Even if true, that empirical claim would not alter the equal protection conclusion set forth above. Under intermediate scrutiny, there still would be a sufficient relationship between the States’ classification based on biological sex and the States’ asserted interests in safety and competitive fairness. In any event, the plaintiffs’ premise is the subject of ongoing medical and scientific debate and is not settled in their direction at this time. States and leading athletic organizations disagree with the plaintiffs and have concluded that biological males still retain a physical advantage after taking puberty blockers and hormones. To take one prominent example, the IOC found that “athletes retain Male performance advantage due in part to training effects and fixed traits. There is no current evidence that testosterone suppression or gender-affirming hormone treatment eliminates this advantage.” IOC, Policy on the Protection of the Female (Women’s) Category in Olympic Sport and Guiding Considerations for International Federations and Sports Governing Bodies (Mar. 26, 2026). The plaintiffs counter with arguments and studies of their own. But in assessing state and federal laws passed under circumstances of “m edical and scientific uncertainty,” this Court has often said that the Judiciary must be cautious about swooping in and invalidating laws. Skrmetti, 605 U. S., at 524 (quotation marks omitted). The legislatures, we have emphasized, maintain “wide discretion to pass legislation” in those circumstances. Ibid. (quotation marks omitted). For good reason. Especially on medical and scientific matters where there is serious debate 25 Cite as: 609 U. S. ____ (2026) Opinion of the Court and disagreement, it can be difficult for courts to meaningfully evaluate the cons idered policy judgments of the lawmakers who have scrutinized the medical evidence and scientific data before them, and have made a reasoned decision. See ibid.; cf. Turner Broadcasting System, Inc. v. FCC, 520 U. S. 180, 195–196 (1997). When there are “open questions regarding basic factual issues before medical authorities and other regulatory bodies,” there is “little basis for judicial respon ses in absolute terms.” Skrmetti , 605 U. S., at 525 (quotation marks omitted). The “calculus of effects, the manner in which a particular law reverberates in a society, is a legislative and not a judicial responsibility.” Ibid. (quotation marks omitted). To be sure, judicial deference does not mean abdication. But the current public medical and scientific record does not definitively establish that the 27 States, the IOC, the USOPC, and the NCAA are wrong in acting on the basis that at least some biological males who have taken puberty blockers or hormones still retain physical advantages over females. In those circumstances, to reiterate, the legislative “institution is far better equipped than the judiciary to amass and evaluate the vast amounts of data,” particularly in cases involving a topic of “inherent complexity.” Turner Broadcasting, 520 U. S., at 195–196 (quotation marks omitted). Indeed, “it is precisely where such disagreement exists that legislatures have been afforded the widest latitude in drafting such statutes.” Kansas v. Hendricks, 521 U. S. 346, 360, n. 3 (1997). Stated simply, “courts should be cautious not to rewrite legislation” “in areas fraught with medical and scientific uncertainties.” Marshall v. United States, 414 U. S. 417, 427 (1974). So it is here. In closing on the equal protection issue, we repeat what the Court said in Skrmetti: 26 WEST VIRGINIA v. B. P. J. Opinion of the Court “This case carries with it the weight of fierce scientific and policy debates . . . in an evolving field. The voices in these debates raise sincere concerns; the implications for all are profound. The Equal Protection Clause does not resolve these disagreements. Nor does it afford us license to decide them as we see best. Our role is not to judge the wisdom, fairness, or logic of the law before us, but only to ensure that it does not violate the equal protection guarantee of the Fourteenth Amendment. Having concluded that it does not, we leave questions regarding its policy to the people, their elected representatives, and the democratic process.” 605 U. S., at 525 (quotation marks and citation omitted). IV Two points in response to the dissent: First, the dissent directs various rhetoric against the Court’s opinion—employing phrases such as “contorted logic” and “misguided approach” and “diminished view of equal protection” and “unencumbered by fact or law.” Post, at 2, 23, 29 (S OTOMAYOR, J., concurring in judgment in part and dissenting in part). With respect, that rhetoric is misdirected. The Court’s holding today is straightforw ard. The Equal Protection Clause allows schools to maintain separate teams for female and male athletes. Schools may determine eligibility for women’s and girls’ teams based on biological sex. That policy is constitutionally justified by the vitally important interests in safety and competitive fairness so as to provide equal opportunities for women and girls to participate in sports. And wh en a sex-based classification is justified as a constitutional matter, as it is here, States need not make case-by-case exceptions—for example, schools need not make individual exceptions to allow 27 Cite as: 609 U. S. ____ (2026) Opinion of the Court certain biological males to compete in women’s and girls’ sports. Second, we do not accept the dissent’s assumed monopoly on understanding the effects on individuals involved in disputes over transgender athletes. We are acutely aware of the difficulties sometimes faced by boys who identify as girls (and by girls who identify as boys) in middle school, high school, and beyond. And we greatly admire the desire of all students, including transgender students such as B. P. J., who want to participate in sports. But in conducting the equal protection inquiry, we must also account for the effects on girls who are forced to compete against biological males in sports. * * * Some might ask: What is the harm in allowing an additional athlete to compete in women’s or girls’ sports? That sentiment, though understandable, misunderstands the nature and reality of sports. Sports are highly competitive and generally zero sum. At almost every turn, someone wins and someone loses. Every athlete who makes a team takes a roster spot from another athlete. Every player who earns playing time reduces the playing time of a teammate. Every player who makes the starting lineup sidelines another who remains on the bench. Every competitor who wins a race or competition deprives another athlete of that victory, or medal, or prize. Every team that wins because of an added player means that another team has lost because of that added player. Every player who makes all-conference beats out another player who does not. Every student who earns an athletic scholarship takes that opportunity away from another student. And so on. Women and girls who play sports care deeply about all of those things. They obsess about them. They spend extraordinary time and effort to train in the heat and in the 28 WEST VIRGINIA v. B. P. J. Opinion of the Court cold, to work out early in the morning and late at night, to get a little faster, to become a little stronger, to jump a little higher, to shoot a little better, to watch a little more video, to make the lonely journey back from an ACL tear, to scrap for playing time, to start, to win the game, to win a championship, to hang a banner, to bring home a medal, to be all-tournament, all-county, all-State, or all-American. They put a championship trophy or all-league award on their bedroom shelf—and it stays there forever as a reminder of their love of the game and pride in their achievements. They learn to endure losses with grace, to lift up their teammates, and to respect opponents who have beaten them fairly and squarely. They learn to win with class—to look a defeated opponent in the eye, shake her hand, and congratulate her on her effort. Whether the star of the team or the last player on the bench, they form lifelong friendships and lifetime memories. They savor their athletic accomplishments and cherish them for years, even decades, after their playing days are over. The two States here—along with 25 other States, the IOC, the USOPC, and the NCAA—have concluded at this time that women and girls should be allowed to compete for those life-changing opportunities on an equal playing field, without fear of physical injury from biological males or being forced to compete against biological males. Consistent with Title IX and the Equal Protection Clause, we hold that the States may maintain women’s and girls’ sports for biological females. They may determine eligibility for women’s and girls’ sports based on biological sex. The Constitution and Title IX do not require an overhaul of women’s and girls’ sports throughout America. In so ruling, we emphasize one last point. Most of the biological female and transgender student-athletes who are involved in transgender sports disputes around the country are teenagers or in their early twenties. Those student- athletes want to play sports. Their desire to compete 29 Cite as: 609 U. S. ____ (2026) Opinion of the Court warrants respect. No student-athlete on either side of the issue, whether a biological female or transgender, deserves to be ostracized or vilified. In B. P. J.’s case, we reverse the judgment of the U. S. Court of Appeals for the Fourth Circuit and remand the case for further proceedings consistent with this opinion. In Hecox’s case, we reverse the judgment of the U. S. Court of Appeals for the Ninth Circuit and remand the case for further proceedings consistent with this opinion. It is so ordered.