Defining Male and Female Act of 2025

Summary

Creates a new federal definition of sex and related terms and requires federal agencies and courts to use those definitions when reading any federal law, rule, or decision. It defines "male" and "female" by biological characteristics present "at conception" tied to sperm and eggs, defines sex as an immutable biological classification, and states that gender identity is an internal sense that the federal government may not treat as a replacement for sex. The measure is limited to definitions and does not itself appropriate money or set implementation deadlines.

• Adds a statutory definitional provision to Title 1 requiring federal actors to use those definitions when interpreting federal law and regulation.
• Defines 'male' and 'female' by biological characteristics present at conception and by reproductive roles (sperm/eggs).
• Declares sex an immutable biological classification of either male or female as defined in the provision.
• Defines gender identity as an internal sense and states the federal government may not treat it as a replacement for sex.
• Applies these definitions across all federal statutes, regulations, rulings, and agency actions.
• Does not appropriate funds, create new programs, or set implementation deadlines—it's a definitional change only.
• Could alter eligibility or access for sex-specific programs, records, data collection, and anti-discrimination protections.
• Likely to prompt litigation and administrative changes as agencies and courts reconcile existing rules with the new definitions.
• May force agencies to revise forms, policies, and guidance that currently recognize gender identity in federal contexts.
• May create conflicts with state laws and existing federal statutes or regulations that use alternative definitions of sex or gender.