According to the Marines, exemption requests are reviewed first by commanders and then sent to a three-person board at Manpower and Reserve Affairs. The board makes a recommendation and the deputy commandant for manpower makes the decision. Marines can appeal any denials to the assistant commandant of the Marine Corps.
All the military services have said the decisions are based not only on the individual request, but also on its impact on the unit, its mission and readiness, and the health and safety of other troops. The Navy and the Marine Corps have said that unvaccinated service members are not allowed to deploy out to sea on ships, where infections can more easily spread.
The Marines, however, have also vastly outpaced the other military services in discharging troops who refuse to get the vaccine. As of Thursday, the Corps had discharged 351 Marines for refusing the shots.
The Air Force said earlier this week that it had discharged 87 airmen, while the Navy has discharged 20 entry-level sailors and the Army has not removed any soldiers from service for refusing the vaccine.
All of the services have granted other medical and administrative exemptions, which are far more common.
As of this week, all of the military services say that at least 97% of their forces have gotten at least one shot.