NEW ORLEANS (AP) — A judge’s order that would eliminate requirements that health insurance plans include cost-free coverage of HIV-preventing drugs, cancer screenings and various other types of preventive care should remain on hold while it is appealed, the Biden administration argued before an appellate panel Tuesday.

It’s the latest legal skirmish over mandates in former President Barack Obama’s signature health care law, commonly known as “Obamacare,” which took effect 13 years ago.

Enforcing the judge’s order could jeopardize preventive care for at least some of an estimated 150 million insured people, Alisa Klein, arguing for the administration, told three 5th U.S. Circuit Court of Appeals judges in New Orleans.

Jonathan Mitchell, arguing for the law’s challengers, said a stay on the ruling is unnecessary. Insurers and employers who provide employee health insurance would be unlikely to drop preventive coverage before the case is finally resolved because they would risk prosecution if they lose, he argued. “No rational employer or insurer can take the risk,” he said.

That drew a skeptical response from Judge Leslie Southwick. “I don’t quite see how that fits into our analysis,” said Southwick, who during the hearing asked attorneys to try to reach an agreement on how and when the lower court ruling should be enforced pending appeal. “You may be right, but it really is speculation if you want us to apply some of our sense of how insurance companies react.”

The March ruling by U.S. District Judge Reed O’Connor affected requirements for coverage driven by recommendations by the U.S. Preventive Services Task Force. O’Connor ruled that because the task force is made up of volunteers, enforcing its recommendations violates the Constitution’s Appointment Clause, which lays out how government officials can be appointed.

As appeals continue, the administration isn’t attempting to block immediate enforcement of O’Connor’s ruling as it applies to the handful of Texas plaintiffs who filed suit. But it should not apply to the millions of people affected nationwide, Klein argued.

Southwick questioned that assertion. “Once the district court decided that all these decisions were beyond the authority of the body that made it, I’m not sure what relief would have been appropriate,” he said.

Not all preventive care is affected under the judge’s ruling. An analysis by the nonprofit KFF foundation found that some screenings, including mammography and cervical cancer screening, would still be covered without out-of-pocket costs because the task force recommended them before the health care law was enacted in March 2010.

O’Connor, a nominee of former President George W. Bush, is the same judge who ruled more than four years ago that the entire Obama health care law was unconstitutional. That ruling was overturned by the U.S. Supreme Court.

Those suing the federal government in this case include a conservative activist and a Christian dentist who oppose coverage for contraception and HIV prevention on religious grounds. The appellate judges are Edith Brown Clement and Southwick, who were also nominated by Bush; and Stephen Higginson, nominated by Obama.

An immediate ruling is not expected.