Arlington National Cemetery has proposed new rules that would curtail the number of individuals eligible for burial there, as the hallowed site is running out of space and hopes to remain open for another 150 years. The Defense Department proposed Wednesday to limit below-ground burial sites only to those killed in action in combat and not veterans who retired from active duty and were eligible for retirement pay. The proposed rules would also allow servicemen who received honors, former prisoners of war, veterans who served as dignitaries, and U.S. presidents and vice presidents to be buried at Arlington, according to to acting Army Secretary Ryan McCarthy.

“Arlington National Cemetery is a national shrine for all Americans, but especially those who have served our great nation,” McCarthy said in the statement. “We must ensure it can honor those we have lost for many years to come.” The Army, which oversees the cemetery, said Arlington “will be closed to new interments by the mid-2050s – even for Medal of Honor recipients” without changes, as there will be no more room for burials.