This Appendix/Figure applies to the following memorandums:

NPRC 1865.20   - Appendix B-2. Meaning of Service Number Prefixes and Suffixes
NPRC 1865.32   - Appendix A. Meaning of Service Number Prefixes and Suffixes
NPRC 1865.104 - Figure A-2. Meaning of Service Number Prefixes and Suffixes

Explanatory notes:
1. The majority of prefixes and suffixes are used for Air Force and Army.

2. None are known to have been used with Coast Guard service numbers.

3. Marine Corps used "O" to denote officer and "W" to denote enlisted women.

4. Navy used "W" to denote enlisted women. Also, from December 1965 Navy enlisted personnel received six digit numbers with a "B" prefix (B100000 thru B999999). Following the "B" series was the "D" series (D100000 thru D999999). Since July 1, 1971, Navy personal identifiers are the nine digit social security number (SSN) with no prefix or suffix.

Character(s)
Used as Armed Force Designation
  A Prefix Army Enlisted Women (WAC without specification of component
  A Suffix Air Force Used until 1965 for Regular AF male officers
  AA Prefix Air Force Women enlisted personnel (WAF)
  AD Prefix Air Force Aviation Cadets
  AF Prefix Air Force Male enlisted personnel other than aviation cadets
  AO Prefix Air Force Reserve officers from about 1947-1965
  AR Prefix Air Force Used until about 1965 for enlisted reserve of the AF and USAF Dieticians
  AW Prefix Air Force Used from about 1947-1965 for male reserve of the AF and USAF Warrant Officers
  E Suffix Air Force Used until 1965 for Regular AF male Warrant Officers
  ER Prefix Army Members of Army Reserve, including those enlisted personnel of Army Nat'l Guard transferred from AUS, RA, or NGUS
  F Prefix Army Used with Field Clerks numbers in 800,000 series in WWI
  FG Prefix Air Force Air National Guard Officers and warrant officers (male and female)
Character(s)
Used as Armed Force Designation
  FR Prefix Air Force Regular AF officers and warrant officers (male and female)
  FR Prefix Army Certain Army enlisted reservists from date unknown through October 3, 1962
  FT Prefix Air Force Officers and warrant officers without component (male and female)
  FV Prefix Air Force Reserve officers and warrant officers
  H Suffix Air Force Used until 1965 for regular AF women warrant officers
  K Suffix Air Force Uses until about 1965 for AF academy cadets
  K Prefix Army Women officers except regular Army with SN's 100,001 or higher, Army Nurse Corps, Army Medical Specialist Corps, and Women's Army Corps
  KF Prefix Army Regular Army Women officers with service numbers 100,001 and higher
  L Prefix Army Women's Army Corps (officers)
  MJ Prefix Army Occupational Therapist Officers
  MM Prefix Army Physical Therapist Officers
  MN Prefix Army Male officers of Army Nurse Corps
  MR Prefix Army Dieticians
  N Prefix Army Female Nurses (officers)
  NG Prefix Army Army National Guard enlisted personnel
  O Prefix Army Male officers except regular Army with SN's 100,001 and higher after October 28, 1963; and Army Nurse Corps and Army Medical Specialist Corps
  O Prefix Marine Corps Officers
Character(s)
Used as Armed Force Designation
  OF Prefix Army Regular Army male officers with SN's 100,001 and higher after October 28, 1963
  R Prefix Army Officer Dieticians
  R Prefix Army Used on Army WWI EM numbers 1 thru 5,999,999 if man reenlisted
  RA Prefix Army Regular Army enlisted personnel (Used since approximately October 1945)
  RM Prefix Army Regular Army EM holding appointments as warrant officer in the active Army reserve
  RO Prefix Army Regular Army enlisted holding commissions in the active Army reserve
  RP Prefix Army Retired EM recalled to Active Duty now on retired status (used only for those transferred to Retired Army reserve).
  RV Prefix Army Women's Army Corps warrant officers holding commissions in active Reserve
  RW Prefix Army Warrant officers holding commissions in active reserve
  T Prefix Army Flight officers appointed from enlisted ranks numbers range from T10,000 thru T223,600 (1942 to date unknown)
  UR Prefix Army Inductees holding commissions or warrants in active Army reserve
  US Prefix Army Enlisted men without specification of component
  V Prefix Army Women Army Corps officers
  W Prefix Army Warrant officers
  W Prefix Marine Corps Women enlisted personnel
  W Suffix Air Force Used until 1965 for Regular AF Women commissioned officers
Character(s)
Used as Armed Force Designation
  W Suffix Navy Women enlisted personnel
  WA Prefix Army Regular Army enlisted women (WAC)
  WL Prefix Army Regular Army enlisted women holding commissions in the active Army reserve
  WM Prefix Army Regular Army enlisted women holding warrants in the Army active reserve
  WR Prefix Army Enlisted women reservists (WAC)