Service members who were kicked out of the U.S. military for refusing the Covid vaccine could be allowed back in uniform if the vaccine mandate is lifted, according to two U.S. military and two senior defense officials.

On Tuesday, the House and Senate released language to be included in the National Defense Authorization Act (NDAA) that requires the Pentagon to lift the mandate. The NDAA, the annual bill that authorizes the military’s budget, must be passed before the end of the year, and Democratic leaders let Republicans include the language in order to ensure its passage.

Pentagon leaders are now discussing whether service members who were separated can rejoin if the NDAA is signed into law, the four officials said. They said requests to rejoin will likely be handled on a case-by-case basis, but if a service member left under good circumstances — meaning they did not leave via an “other than honorable” discharge — they may be allowed to sign back up.

Defense Secretary Lloyd Austin ordered in August 2021 that all active-duty National Guard and Reserve service members be vaccinated for Covid or face separation. The NDAA language directs Austin to rescind his order. It is very unusual for Congress to intervene and overturn a standing lawful order, two senior defense officials said, noting they could not immediately recall any precedent.

After Austin issued his mandate, thousands of active-duty service members were separated for refusing the Covid vaccine. (Members of the National Guard who refused the vaccine were not allowed to participate in drills or training, meaning they lost pay and were marked absent without cause.)

In many cases, the official reason for separation was failing to follow a lawful order. But if an enlisted service member who was separated has no other bar to re-enlistment, still meets the age and fitness standards and wants to rejoin, they could now be allowed back in in the mandate is repealed, said one U.S. military and one defense official. The officials said the enlisted service member may not be able to get back in at the same pay grade or rank, but that will be a case-by-case decision.

Officers will likely be held to a different standard, the two officials said. If they left for failing to obey a lawful order, even if it is no longer a lawful order, they may not be allowed to reinstate their commissions.

Pentagon leaders are concerned about how this change will impact military readiness going forward, according to two senior defense officials, both of whom are not confident the majority of troops will continue to get vaccinated without the mandate.

Service members often live and work in close quarters like ships and barracks, making infectious diseases more worrisome. The lack of a vaccine mandate will likely impact deployability and readiness for troops, the officials said. Not only will illness make some troops nondeployable, they said, but some countries won’t admit people who refuse to be vaccinated, so unvaccinated troops cannot necessarily participate in exercises or be stationed overseas.

On Wednesday, Pentagon deputy press secretary Sabrina Singh declined to provide specifics about how revoking the mandate could impact troops and operations in the future, including whether unvaccinated troops will be deemed deployable. “We don’t comment on pending legislation,” she said, adding that she would not get into “hypotheticals.” Secretary Austin supports keeping the vaccine mandate, she said, and when pressed she said repealing the vaccine will impact readiness. 

Singh said that 691 service members, DOD civilians and dependents have died from Covid.

The vast majority of active-duty service members are now vaccinated — only about 2% have not received both doses of the vaccine — but ending the mandate will mean new recruits will not need to get the vaccine.

Some U.S. military officials are also concerned this case could provide a roadmap for disgruntled troops on how to protest in the future, according to the two senior officials. If there is a politically charged issue, they now have proof that they can lobby their members of Congress and get a lawful order overturned, even if military leaders and the Secretary of Defense disagree.

Rep. Greg Murphy, R-N.C., a longtime opponent of the vaccine mandate, said, “While this repeal will bring relief to many in our U.S. Armed Forces, we must go further to re-enlist those who were discharged for not taking the vaccine and hold the Biden administration accountable for this damaging, politically targeted ploy at the expense of America’s heroes.”