Defining Male and Female Act of 2025

This bill aims to establish clear and consistent biological definitions for "sex," "male," "female," and related terms for use across all Acts of Congress and federal agency rulings. It defines a female as a natural person belonging, at conception, to the sex characterized by a reproductive system with the biological function of producing eggs (ova), and a male as a natural person belonging, at conception, to the biological sex characterized by a reproductive system with the biological function of producing sperm.

The legislation further clarifies that sex, when referring to a natural person, means an immutable biological classification as either male or female, as determined and defined by this section. It also defines gender identity as an internal and subjective sense of self disconnected from biological reality, stating it shall not be recognized by the Federal Government as a replacement for sex. Other terms such as "boy," "girl," "man," "woman," "father," and "mother" are also provided with biological definitions.