TX SB406

Requires Texas birth certificates to include a space for recording biological sex as either male or female, determined by sex organs, chromosomes, or endogenous profile

Prohibits registrars and courts from issuing amended birth certificates that change the biological sex designation, with limited exceptions

Allows sex designation changes only to correct clerical errors, complete missing information, or for individuals born with medically documented atypical or ambiguous sex characteristics whose sex is later determined by a physician

Exempts children born with physician-documented atypical or ambiguous sex organs, chromosomes, or endogenous profile from the requirement to list biological sex at birth, allowing later amendment once sex is determined

Directs the Health and Human Services Commission to adopt rules implementing these changes, with an effective date of September 1, 2025