Senator Marshall Introduces the Defining Male and Female Act of 2025

Washington – U.S. Senator Roger Marshall, M.D. (R-Kansas) today introduced the Defining Male and Female Act of 2025, a bill codifying the legal definitions of male, female, and sex to ensure they are based on biological reality rather than radical, left-wing ideology. 

This bill specifically would enshrine into law President Trump’s Executive Order entitled “Defending Women From Gender Ideology Extremism and Restoring Biological Truth to the Federal Government,” which clarifies that sex is determined at conception and is dependent on the size of reproductive cells and ensures the federal government uses this sex dichotomy.

“The Democrats’ radical transgender agenda is dangerous and wrong. We shouldn’t need legislation to tell us the basic reality that there are only two sexes, but here we are,” Senator Marshall said. “I’m thankful President Trump has made this a top priority and signed an Executive Order on his first day in office recognizing that there are only two sexes. Congress must ensure this historic action is written into law by passing the Defining Male and Female Act.”

U.S. Representative Mary Miller (R-Illinois-15) introduced the House companion version of the bill. 

“Now more than ever, we must unite to uphold the truth and biological reality established by God that there are only two sexes,” said Congresswoman Mary Miller. “I am proud to stand alongside Senator Marshall in introducing the House companion to the Defining Male and Female Act to ensure our nation upholds common sense and puts an end to the Left’s dangerous and extreme sexual fantasies.”

Senator Marshall’s bill is cosponsored in the Senate by Senators Bill Cassidy (R-Louisiana), Tim Sheehy (R-Montana), Cindy Hyde-Smith (R-Mississippi), and Pete Ricketts (R-Nebraska).

“Common sense and science tell us there are two sexes,” said Senator Cassidy. “You are born a male or a female.”

“Boys are boys, girls are girls, and gone are the days of woke nonsense like calling mothers ‘birthing persons.’ Supporting this legislation is a no-brainer and I’m proud to be restoring common sense in America,” Senator Sheehy said.

“By affirming biological truth, we defend fairness in sports, safeguard women and children, and uphold the principles of Title IX as Congress intended,”Senator Hyde-Smith said. “Because the other side spent four years pretending boys were girls, it’s time to restore common sense once and for all by establishing clear, legal, and biologically-accurate definitions of male and female.”

“This bill is simple. It defines the most basic science. There are only two sexes: male and female,” Senator Ricketts said. “Defining males and females is an important step to helping protect our women and girls across America.”

Click HERE to read the full bill text.

BACKGROUND:

Specifically, the Defining Male and Female Act recognizes:

• The definition of male and female on the basis of a person belonging, at conception, to the sex characterized by a reproductive system with the biological function of producing eggs or producing sperm.
• The right of girls and women to sex-separate sports and scholarships.
• The sex separation of restrooms, locker and dorm rooms, prisons, and shelters for victims of sexual assault.

Senator Marshall has been a leader in defending biological reality and protecting children from radical gender ideology. His actions include:

• Introducing the End Taxpayer Funding of Gender Experimentation Act, legislation that prohibits the use of federal funding for gender transition procedures and bars federal healthcare facilities, physicians, and providers from providing such procedures.
• Leading landmark legislation, the Safeguarding the Overall Protection of Minors Act, which would protect America’s children from the irreversible physical and emotional harm caused by transgender procedures.
• Supporting the Protection of Women and Girls in Sports Act, legislation that would save girls’ and women’s sports and preserve Title IX protections for female athletes.

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