Michigan 2025-2026 Regular Session

Michigan House Bill HB4066

Introduced
2/11/25  
Refer
2/11/25  
Report Pass
5/15/25  
Engrossed
5/22/25  

Caption

House Bill 4066 of 2025

Summary

HB4066 would amend Michigan’s Revised School Code to require school districts, intermediate school districts, and public school academies that participate in interscholastic athletics to designate teams and sports as female, male, or coeducational. It would prohibit schools from knowingly allowing students of the male sex to compete on teams designated for the female sex, while preserving eligibility for male-designated or mixed teams. The bill defines “sex” as the biological indication of male or female shown on an individual’s original birth certificate. The bill also limits outside enforcement actions by state agencies, political subdivisions, accrediting organizations, and interscholastic athletic associations. Those entities would be barred from processing complaints, opening investigations, or taking adverse action against schools for maintaining separate single-sex girls’ teams. In addition, the bill creates private rights of action for students who are harmed by a violation, for students who face retaliation after reporting a violation, and for school districts harmed by a prohibited enforcement action. Any lawsuit would have to be filed within two years of the alleged violation.

Impact

HB4066 would add a new section to the Revised School Code and directly regulate how public school athletic teams are classified and administered in Michigan. It would affect school districts, intermediate school districts, and public school academies that offer interscholastic sports, and it would also constrain the role of state agencies, accrediting bodies, and athletic associations in policing sex-segregated girls’ athletics. The bill would create new civil liability exposure and enforcement mechanisms, including damages and injunctive relief, for both schools and individuals depending on the nature of the alleged violation.

Sentiment

The available voting history suggests the bill was supported by a majority but remained contested. It was reported from committee on a narrow 3-2 vote, indicating division at the committee level, and then passed the House on third reading 58-46, showing a closer floor vote than many broadly supported education measures. No committee transcript is available, but the vote pattern indicates substantial support from proponents and significant opposition from opponents.

Contention

The main point of contention is the bill’s treatment of sex-based eligibility in school sports, especially the exclusion of students of the male sex from female-designated teams and the bill’s definition of sex by original birth certificate. Supporters are likely focused on preserving single-sex girls’ athletics and limiting outside enforcement against schools that maintain those teams. Opponents are likely concerned about discrimination against transgender students, the restriction on participation opportunities, and the bill’s private right of action and limits on complaints or investigations by oversight bodies. The enforcement provisions and the biological-sex definition are the most legally and politically sensitive parts of the measure.

Companion Bills

No companion bills found.

Previously Filed As

MI HB4469

Civil rights: sex discrimination and harassment; basing an individual's eligibility to participate in athletics on the individual's biological sex; provide an exemption to allow certain K-12 educational institutions to do. Amends 1976 PA 453 (MCL 37.2101 - 37.2804) by adding sec. 405.

MI HB4027

INTERSCHOLASTIC ATHLETICS-TEAM

MI HCR2003

Interscholastic; intramural athletics; biological sex

MI HB1117

INTERSCHOLASTIC SPORTS-GENDER

MI HB1204

INTERSCHOLASTIC SPORTS-GENDER

MI HB1216

INTERSCHOLASTIC SPORTS-GENDER

MI SB211

Relative to biological sex in student athletics.

MI SB211

relative to biological sex in student athletics.

MI HB233

Protection Of Women's Sports Act

MI LD2239

An Act to Designate School Sports Participation and Facilities by Sex

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