(The Hill) The Federal Bureau of Prisons may not enforce parts of a sweeping executive order President Donald Trump signed on his first day back in office instructing it to cease treatment for transgender inmates’ gender dysphoria, a federal judge ruled Tuesday. 

Judge Royce C. Lamberth of the U.S. District Court for the District of Columbia temporarily blocked the agency from enforcing Trump’s order while a legal challenge against it continues. 

The Jan. 20 order, which proclaims the U.S. recognizes only two sexes, male and female, and broadly prohibits federal spending on “gender ideology,” tasks Attorney General Pam Bondi with barring the agency from expending funds “for any medical procedure, treatment, or drug for the purpose of conforming an inmate’s appearance to that of the opposite sex.” 

It directs Bondi and Homeland Security Secretary Kristi Noem to ensure “that males are not detained in women’s prisons or housed in women’s detention centers.” In a separate ruling, Lamberth blocked the administration in February from moving three trans women to men’s facilities. 

A BOP memo issued in February directed agency officials to comply with Trump’s order by preventing transgender inmates from purchasing “any items that align with transgender ideology,” such as chest binders and hair removal devices, and mandating prison staff to refer to trans individuals using only “pronouns that correspond to their biological sex.” A second memo, issued Feb. 28, barred agency funds from being used for transition-related medical care. 

Three transgender inmates two men and one woman sued the Trump administration in March, arguing that denying them their hormone treatment violates the Eighth Amendment’s prohibition on cruel and unusual punishments. Each of the plaintiffs, serving sentences in facilities in New Jersey, Minnesota and Florida, was diagnosed with gender dysphoria by a BOP medical provider and either had their hormone treatments suspended or were told they would soon. 

Lamberth, an appointee of former President Ronald Reagan, wrote Tuesday in his ruling that the plaintiffs suffer irreparable harm and are likely to succeed in arguing that the agency’s actions are “arbitrary and capricious” and violate the Administrative Procedure Act. 

“In light of the plaintiffs’ largely personal motives for undergoing gender-affirming care, neither the BOP nor the Executive Order provides any serious explanation as to why the treatment modalities covered by the Executive Order or implementing memoranda should be handled differently than any other mental health intervention,” he wrote. 

Lamberth also agreed on Tuesday to certify a class of individuals in BOP custody who have been diagnosed with or meet the criteria for gender dysphoria and would receive gender-affirming care. 

“This is a critical ruling for our clients and all transgender people in Bureau of Prisons custody,” said Corene Kendrick, deputy director of the American Civil Liberties Union’s National Prison Project, which is representing the plaintiffs alongside the ACLU of DC and the Transgender Law Center. 

“No person incarcerated or not, transgender or not should have their rights to medically-necessary care denied,” Shawn Thomas Meerkamper, managing attorney at the Transgender Law Center, said Tuesday in a statement. “We are grateful the court understood that our clients deserve basic dignity and healthcare, and we will continue to fight alongside them.” 

The Justice Department did not immediately return a request for comment on Lamberth’s ruling.