A U.S. judge on Wednesday blocked the Biden administration from enforcing a new rule against discrimination on the basis of gender identity in health care.

U.S. District Judge Louis Guirola in Gulfport, Mississippi, sided with 15 Republican-led states that sued to challenge the rule, arguing that it exceeded the administration’s authority.

The rule was finalized in May and was set to take effect on Friday. It states that a federal prohibition on sex discrimination, part of the Affordable Care Act health insurance law, extends to discrimination against transgender people.

The U.S. Department of Health and Human Services, which issued the rule, did not immediately respond to a request for comment.

The rule came after President Joe Biden, a Democrat, in a 2022 executive order instructed federal agencies like HHS to take measures ensuring transgender people’s access to health care.