Also noteworthy apropos of long service, is that a USAF GCM will be granted during wartime after one full year of service.
To wit:
Criteria
It was awarded to Air Force enlisted personnel during a three-year period of active military service or for a one-year period of service during a time of war. Airmen awarded this medal must have had character and efficiency ratings of excellent or higher throughout the qualifying period including time spent in attendance at service schools, and there must have been no convictions of court martial during this period. Air Force personnel who were previously awarded the Army Good Conduct Medal and after June 1, 1963 qualified for the Air Force Good Conduct Medal could wear both medals.