A federal appeals court on Friday allowed a lawsuit to go forward challenging the U.S. military’s decision to discharge certain service members who test HIV-positive, saying it appears the Pentagon unlawfully discriminates against them based on a medical condition.

The unanimous decision by a three-judge panel of the Richmond-based U.S. Court of Appeals for the 4th Circuit marked a setback for the Pentagon, which has sought to toss out the lawsuit by two airmen whom the Air Force moved to force out after the results of health screenings last year.

The Defense Department restricts newly diagnosed personnel from deploying to combat zones such as Afghanistan. The government asserts that the risk of HIV transmission is heightened on the battlefield, where it may be more difficult to maintain treatment.

But in arguments in September, judges asked why the military would refuse to deploy service members with HIV but not those with other chronic conditions such as diabetes and high blood pressure.

Writing for the panel, U.S. Circuit Judge James A. Wynn Jr. said plaintiffs were likely to show the military acted “arbitrarily or capriciously” in violation of the Administrative Procedures Act by discharging service members without an individualized fitness assessment. Read more via Washington Post