Service number (United States Air Force)

United States Air Force service numbers were created in the spring of 1948, approximately six months after the Air Force's creation as separate branch of the armed forces.

The first regulation of Air Force service numbers applied to numbers held by Air Force officers. In 1947, thousands of officers had automatically transferred from the Army Air Forces into the Air Force, with over a third of this number inactive members of the Officer Reserve Corps. The first Air Force officer service numbers ranged from 1 to 19,999 and were reserved for Regular Air Force officers who had "crossed over" to the United States Air Force.

A complication to early service number issuance was that some senior Air Force officers (such as Henry H. Arnold) choose to simply retain their Army service numbers and did not apply for a new Air Force service number. Thus, the earliest Air Force officer service number was #4 which was assigned to Hoyt Vandenberg; numbers one through three were apparently never issued.

After the initial issuance of the first Air Force officer service numbers, the service numbers were increased with the second range extending from 20 000 to 99 999. These numbers were set aside for past, present, and future Regular Air Force officers with this range being used from 1948 until the discontinuation of Air Force service numbers in 1969.

For a brief time in the 1950s until 1965, cadets at the United States Air Force Academy were assigned a special range of service numbers only for use while attending the Academy. These numbers ranged from 1 to approximately 7000 based on admission date to the Academy. These numbers were followed by the suffix "K" and were not part of the regular Air Force service number system.

The service numbers 100 000 to 1 799 999 were never used by the Air Force office corps to avoid repeating numbers already assigned to Army officers; the only Air Force officers who ever held these numbers were those who had received their commissions under the authority of the Army Air Forces. The next range of Air Force officer service numbers began at 1 800 000 and extended to 1 999 999; these numbers were assigned to former reserve officers of the Army Air Forces who were now members of the Air Force Reserve. The two million number range was never issued by the Air Force, to avoid repeating service numbers of the Army, with the next range beginning at 3 000 000 and extending to 3 999 999. These numbers were intended for all officers considered "Other Than Regular Air Force" (OTRAF) and were issued in chronological order by date of commission after 1948. Such numbers were normally preceded with a zero.

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