Defining Male and Female Act of 2025

This bill defines biological sex for federal law by amending Title 1 of the U.S. Code. It specifies that "female" means a person biologically characterized by egg-producing systems at conception, "male" means sperm-producing systems at conception, and "gender identity" is not recognized as replacing biological sex in federal contexts. The law directly affects all federal agencies, departments, and laws requiring interpretation of terms like "sex," "female," or "male" by mandating these biological definitions. It does not create new programs or funding but changes how federal agencies must interpret existing laws and regulations.