Service numbers were used by the United States Department of Defense as the primary means of service member identification from 1918 until 1974 (and before 1947 by the U.S. Army and U.S. Navy). Service numbers are public information available under the Freedom of Information Act, unlike social security numbers which are protected by the Privacy Act of 1974.[1]
Each branch of the military service had its own version of service numbers. In order by year of creation, these were:
The following are the original service numbers which were first issued to United States military personnel:[2]
The original Air Force enlisted force was composed of personnel formerly of the United States Army Air Forces who continued to use their Army service numbers upon transfer to the Air Force in 1947. Thus, there is no established "first" enlisted service number of the U.S. Air Force since thousands of airmen simultaneously transferred into the Air Force on 18 September 1947.[3]
Service numbers were eventually phased out completely by the social security number; the Army and Air Force converted to social security numbers on 1 July 1969, the Navy and Marine Corps on 1 January 1972, and the Coast Guard on 1 October 1974.[4] Since that time, social security numbers have become the de facto military service number for United States armed forces personnel.
Beginning in 2002, the military began a further effort to protect the use of social security numbers, even within the military itself. New regulations declared that on all but the most official of documents (such as a DD Form 214 or evaluation reports) social security numbers would only list the last four digits. Regulations also were enacted to redact the social security number of reporting seniors (which were written in their entirety) on the personal copies of evaluation reports given to service members. The reason for this was to prevent possible identity theft issues committed by service members who had received a bad evaluation or who were disgruntled with their commanding officer.[5]
The general design of United States service numbers was created first by the United States Army and later adapted by the other branches of the armed forces. Between each branch, service numbers are assigned differently while some branches make a conscious effort to separate officer and enlisted numbers while others do not. It is therefore common in the U.S. service number system for officers and enlisted personnel to perhaps hold the same service number and even more common for service members from different branches to be assigned the same number as well.
The Army is the only branch of service to begin both officer and enlisted service numbers at No. 1. Marine Corps officer numbers also begin at No. 1 but Marine Corps enlisted numbers start much later at #20,001. There is also no service No. 1 in the Navy, Coast Guard, or Air Force although the earliest recorded Air Force officer number was No. 4.
The entire range of United States service numbers extends from 1 to 99,999,999 with the United States Army and Air Force the only services to use numbers higher than ten million. A special range of numbers from one to seven thousand (1–7000) was also used by the United States Air Force Academy for assignment only to cadets and was not considered part of the regular service number system. Another unique service number series was the National Guard which used service numbers solely in the range of twenty to twenty nine million (20,000,000 – 29,999,999).
| Service Number | Army Enlisted | Army Officer | Navy Enlisted | Navy Officer | Air Force Enlisted | Air Force Officer | Marine Enlisted | Marine Officer | Coast Guard Enlisted | Coast Guard Officer |
| 1–100 | World War I enlisted personnel | World War I officers | Not issued | Not issued | Not issued | Senior Air Force officers formerly of the Army Air Forces | Not issued | World War I officers | Not issued | Not issued |
| 101–500 | USMC Officers (1920s) | |||||||||
| 501–1000 | Navy Officers (1920) | |||||||||
| 1001–2000 | Navy Officers (1920s – 1930s) | USMC Officers (1930–1941) | Regular USCG Officers (1921–1974) | |||||||
| 2001 – 10,000 | USMC Officers (World War II) | |||||||||
| 10,001 – 20,000 | Regular Army officers (1920s/1930s) | B" & "D" Series Numbers (1965–1971) | ||||||||
| 20,001 – 30,000 | Regular USAF Officers (1948–1969) | Retroactive (1905–1917) | Reserve/Warrant USCG Officers (1921–1950s) | |||||||
| 30,001 – 50,000 | Regular Army officers (1940s/1950s) | |||||||||
| 50,001 – 60,000 | Not issued | USMC Officers (1948–1966) | ||||||||
| 60,001 – 70,000 | Regular Army officers (1950s/1960s) | Retroactive (1905–1919) | Non-Regular USCG Officers (1950s/1960s) | |||||||
| 70,001 – 80,000 | Non-Regular USCG Officers (1960s/1970s) | |||||||||
| 80,001 – 90,000 | "Special Use" service numbers | |||||||||
| 90,001 – 99,999 | Regular Army (Late 1960s) | |||||||||
| 100,000 – 125,000 | Not issued | USMC Enlisted (1920–1935) | USMC Officers (1966–1972) | USCG Enlisted (1920s/1930s) | Not issued | |||||
| 125,001 – 140,000 | Navy Officers (World War II) | Not issued | ||||||||
| 140,001 – 150,000 | Officer Reserves (1920s – 1941) | |||||||||
| 150,001 – 200,000 | Retroactive Service Numbers | |||||||||
| 200,001 – 255,000 | USMC Enlisted (1936–1941) | USCG Enlisted (World War II) | ||||||||
| 255,001 – 350,000 | USCG Enlisted (1945–1962) | |||||||||
| 350,001 – 500,000 | Navy Officers (1945–1955) | USMC Enlisted (Early World War II) | USCG Enlisted (1962–1974) | |||||||
| 500,001 – 600,000 | Officer Reserves (1942–1954) | USCG Enlisted (World War II) | ||||||||
| 600,001 – 671,000 | Navy Officers (1955–1963) | |||||||||
| 671,001 – 700,000 | Navy Officers (1964–1969) | Not issued | ||||||||
| 700,001 – 800,000 | USMC Female Enlisted | |||||||||
| 800,001 – 1,000,000 | Special Duty Officers (1921–1969) | Not issued | USMC Enlisted (Mid World War II) | |||||||
| 1,000,001 – 1,700,000 | Army Officers (1942–1954) | Enlisted Series 100 (Retroactive) | USMC Enlisted (1943–1953) | Not issued | ||||||
| 1,700,001 – 1,800,000 | USMC Female Enlisted | |||||||||
| 1,800,001 – 2,000,000 | Early Air Force Reserve | USMC Enlisted (1953–1965) | ||||||||
| 2,000,001 – 2,800,000 | Enlisted Series 200 (1920–1971) | Not issued | USMC Enlisted (1966–1972) | USCG Enlisted (1948–1974) | ||||||
| 2,800,001 – 2,999,999 | Not issued | |||||||||
| 3,000,000 – 3,999,999 | Warrant officers (1957–1969) | Enlisted Series 300 (1920–1971) | Air Force officers (1948–1969) | World War II (Special Duty) | ||||||
| 4,000,000 – 4,999,999 | Army officers (1954–1957) | Enlisted Series 400 (1920–1971) | Not issued | Female enlisted (1942–1945) | ||||||
| 5,000,000 – 5,999,999 | Army officers (1957–1969) | Enlisted Series 500 (1920–1971) | Special Duty enlisted (1942) | |||||||
| 6,000,000 – 6,999,999 | Army enlisted (1919–1941) | Not issued | Enlisted Series 600 (1920–1971) | World War II (Special Duty) | ||||||
| 7,000,000 – 7,100,000 | Enlisted Series 700 (1920–1971) | USCG Enlisted (1943–1945) | ||||||||
| 7,100,001 – 7,999,999 | Not issued | |||||||||
| 8,000,000 – 8,999,999 | Female enlisted (1948–1969) | Enlisted Series 800 (1920–1971) | Female enlisted (1948–1969) | Not issued | ||||||
| 9,000,000 – 9,999,999 | Not issued | Enlisted Series 900 (1920–1971) | Not issued | |||||||
| 10,000,000 – 10,999,999 | Regular Army (Enlisted Extra-US) | Not issued | Regular Air Force | |||||||
| 11,000,000 – 19,999,999 | Regular Army | |||||||||
| 20,000,000 – 29,999,999 | Army National Guard | Air National Guard | ||||||||
| 30,000,000 – 30,999,999 | World War II draftees (Extra-US) | WWII crossover #s | ||||||||
| 31,000,000 – 39,999,999 | World War II draftees | |||||||||
| 40,000,000 – 49,999,999 | Special duty enlisted | |||||||||
| 50,000,000 – 59,999,999 | Army draft force (P-WWII) | Air Force draft force (1948–1966) | ||||||||
| 60,000,000 – 69,999,999 | Army draft force (Late 1960s) | Air Force draft force (1966–1969) | ||||||||
| 70,000,000 – 89,999,999 | Not issued | Not issued | ||||||||
| 90,000,000 – 99,999,999 | Philippine Army Augments (WWII) | |||||||||
Service number prefix and suffix codes were one and two letter designators written before or after a service number; a service member could only have one code at any given time. The purpose of these codes was to provide additional information regarding a military service member with the very first prefix codes created by the Army in 1920 and greatly expanded over the next thirty years. The Navy created the first suffix code "W", written after the service numbers of female enlisted personnel, but it was the Air Force that made the greatest use of suffix codes until 1965 when the Air Force switched to using prefixes. Some prefix and suffix codes were also re-introduced, with different meanings, by various branches of military. In the modern age, the only code that survives is the suffix code "FR", written after the social security numbers of Regular Air Force personnel.
| Service Number Code | Branch of Service | Prefix/Suffix | Meaning |
| A | Army & Air Force | Prefix & Suffix | As a prefix, used by members of the Women Army Corps. As a suffix, used by Regular Air Force officers until 1965. |
| AA | Air Force | Prefix | Used by personnel of the "Women in the Air Force" (WAF) |
| AD | Air Force | Prefix | Used by Air Force aviation cadets |
| AF | Air Force | Prefix | Used by male Air Force enlisted personnel |
| AO | Army & Air Force | Prefix | First used by the Army Air Corps to denote Regular Army officers who were qualified in aviation. Later used by the Army Air Forces (and eventually the Air Force Reserve) to denote reserve officers |
| AR | Air Force | Prefix | Used by Air Force dieticians |
| AW | Air Force | Prefix | Used by Air Force warrant officers |
| B | Navy | Prefix | Used between 1965 and 1971 as part of the "B-Series" enlisted service numbers |
| D | Navy | Prefix | Used between 1969 and 1971 as part of the "D-Series" enlisted service numbers |
| E | Air Force | Suffix | Used by male Air Force warrant officers until 1965 |
| ER | Army | Prefix | Used by enlisted members of the Army Reserve |
| F | Army | Prefix | Used by field clerks during the First World War |
| FG | Air Force | Prefix | Used by officers and warrant officers of the Air National Guard |
| FR | Army & Air Force | Prefix & Suffix | Used briefly as an Army prefix by some enlisted members of the Army Reserve. Later used as an Air Force prefix for all officers and warrant officers of the Regular Air Force. After 1969, used as a suffix for Regular Air Force officers, written after the social security number. |
| FT | Air Force | Prefix | Used by Air Force officers and warrant officers who were without a component |
| FV | Air Force | Prefix | Used by Air Force Reserve officers and warrant officers |
| H | Air Force | Suffix | Used by female Air Force warrant officers until 1965 |
| K | Army & Air Force | Prefix & Suffix | As a prefix, used by female specialist officers with service numbers of 100,001 and higher. As a suffix, used by Air Force Academy cadets until 1965 |
| KF | Army | Prefix | Used female Regular Army officers |
| L | Army | Prefix | Used by enlisted members of the Women's Army Corps |
| MJ | Army | Prefix | Used by Occupational Therapist Officers |
| MM | Army | Prefix | Used by Physical Therapist Officers |
| MN | Army | Prefix | Used by male members of the Army Nurse Corps |
| MR | Army | Prefix | Used by Army enlisted dieticians |
| N | Army | Prefix | Used by female nurse officers |
| NG | Army | Prefix | Used by National Guard personnel |
| O | Army | Prefix | Originally used by Regular Army officers prior to World War II. In the 1960s, used by Army specialist officers. |
| OF | Army | Prefix | Used by male Regular Army officers |
| R | Army | Prefix | Originally used by Regular Army World War I enlisted personnel. In the 1960s, used by Army officer dieticians |
| RA | Army | Prefix | Used by Regular Army enlisted personnel |
| RM | Army | Prefix | Used by Regular Army enlisted personnel holding temporary commissions as warrant officers |
| RO | Army | Prefix | Used by Regular Army enlisted personnel holding temporary reserve officer commissions |
| RP | Army | Prefix | Used by retired Regular Army enlisted personnel upon recall to active duty |
| RV | Army | Prefix | Used by female warrant officers granted reserve commissioned officer billets |
| RW | Army | Prefix | Used by male warrant officers granted reserve commissioned officer billets |
| T | Army | Prefix | Used by flight officers appointed from an enlisted status |
| UR | Army | Prefix | Used by draft peronnel who are later appointed officers in the Regular Army |
| US | Army | Prefix | Used by enlisted draft personnel of the Army of the United States |
| W | Army, Air Force, Navy, & Marine Corps | Prefix & Suffix | As a prefix, used by Regular Army Warrant Officers. Also used by female Regular Air Force officers and female Marine Corps enlisted personnel. As a suffix, used by Navy female enlisted personnel |
| WA | Army | Prefix | Used by enlisted members of the Women's Army Corps |
| WL | Army | Prefix | Used by female Regular Army personnel granted officer commissions in the Army Reserve |
| WM | Army | Prefix | Used by female Regular Army personnel granted warrant officer commissions in the Army Reserve |
| WR | Army | Prefix | Used by female enlisted reservists of the Women's Army Corps |