Montana health officials have adopted a new rule that individuals cannot change their biological sex on a birth certificate even if they undergo sexual reassignment surgery.

The new rule comes after a judge temporarily struck down a similar law in April, which the state restored in May, the Associated Press (AP) reported.

The initial law had a provision that allowed individuals to change their sex on a birth certificate following a sex reassignment procedure. That law was passed by the Montana legislature and signed by Gov. Greg Gianfore (R) in 2021

On Friday, the Montana Department of Public Health and Human Services (DPHHS) changed that provision of the law, stating that individuals cannot change their sex on a birth certificate unless under a rare circumstance – such as a data entry error.

An individual’s sex on a birth certificate can only be listed as male or female, according to the law.

The DPHHS stated in the text of the new provision that sex is “immutable” and that “no surgery changes a person’s sex,” while also stating that gender is a “social construct.” The department cited various medical studies for its reasoning.

The change became official on Saturday, the Hill reported.

The DPHHS’s Friday announcement comes after the department used similar reasoning in June to consider adopting the now implemented provision.

The ACLU – which represented transgender individuals in the court case that struck down the first iteration of the law in April – criticized the DPHHS’s new provision. The group also criticized the state for “non-compliance” with the judge’s previous order.

District Court Judge Michael Moses, who temporarily barred the 2021 law, wrote in his decision that the law encroaches on an individual’s right to privacy, KTVH reported in April.

“To obtain a court order, plaintiffs must publicly disclose confidential, intimate details of their medical treatment,” Moses stated.

“Only transgender individuals are subjected to these procedures and burdens in order to have a birth certificate that accurately reflects their gender.”

The judge will hear the case again regarding the new rule on Thursday in Billings.

Similar legislation prohibiting changing an individual’s sex on a birth certificate exists in Tennessee, Oklahoma, and West Virginia, while being struck down in Ohio and Idaho in 2020, the AP noted.

You can follow Ethan Letkeman on Twitter at @EthanLetkeman.