M21-1 Manual  /  Part III, Subpart ii, Chapter 2, Section H

Service Department Organizational Structures and Service Number Assignments

M21-1, Part III, Subpart ii, Chapter 2, Section H

Overview

In This Section

 This section contains the following topics:
TopicTopic Name
1 Army Organizational Structure
2 Navy Organizational Structure
3 Air Force Organizational Structure
4 Marine Corps Organizational Structure
5 Guide for Service Numbers 1 through 9,999,999
6 Guide for Service Numbers 10,000,000 through 19,999,999
7 Guide for Service Numbers 20,000,000 and Higher


1. Army Organizational Structure

Introduction

 This topic contains information on the Army organizational structure, including
  • Army echelons and appropriate designations
  • availability of organizational records, and
  • other organizational units that may have created records.

Change Date

 December 13, 2005

III.ii.2.H.1.a. Army Echelons and Appropriate Designations

 The table below lists the Army echelons and appropriate designations.
EchelonsDesignations
Army Numerical/Geographical
Corps Roman numeral
Division Numerical by combat arm
Brigade Numerical or combat command, such as Alpha
Regiment Numerical by combat arm
Group Numerical by combat arm
Battalion Numerical/battle group numerical/squadron numerical
Company Alpha/Battery - Alpha/Troop - Alpha
Platoon Numerical/Detachment – Numerical
Squad Numerical
Fire Team ---

III.ii.2.H.1.b. Availability of Organizational Records

 Rosters, morning reports, and sick reports may be available down to the company level. Note: The Army discontinued morning reports in 1974/1975.

III.ii.2.H.1.c. Other Organizational Units that May Have Created Records

 Records, including clinical and medical records, may exist for other organizations and units, such as
  • garrison-type units, and
  • hospitals.
Important: If a unit was considered independent from higher echelons, it may have created its own records.


2. Navy Organizational Structure

Introduction

 This topic contains information on the Navy organizational structure, including
  • Navy echelons and appropriate designations
  • echelons for the
    • Naval Air Force
    • Naval Surface Force, and
    • Naval Submarine Force
  • ship designations, and
  • shore establishment organization.

Change Date

 August 13, 2009

III.ii.2.H.2.a. Navy Echelon and Appropriate Designations

 The table below lists the Navy echelon and appropriate designations. For clarification, samples of unit designations are shown in italics.
EchelonDesignations
Fleet-Atlantic Pacific Numbered fleets
Fleet Numerical (7th Fleet; 7thFlt.)
Task force Task force number and type of force (CTF-45 Battle Force) Notes:
  • Task forces are operational sub-units of fleets organized to perform specific missions for the fleet.
  • The following are Naval Task forces:
    • the Naval Air Force
    • the Naval Surface Force, and
    • the Naval Submarine Force.
Fleet Marine Force Reference: For more information on the Fleet Marine Force, see M21-1, Part III, Subpart ii, 2.H.4.
U.S. Naval Forces Europe ---
Middle East Force-Persian Gulf ---

III.ii.2.H.2.b. Echelon for the Naval Air Force

 The following list shows the echelon for the Naval Air Force:
  • carrier strike group (CSG 5)
  • carrier air wing, and (CVW-2)
  • squadron (VFA-2; VAQ-131)
Notes:
  • Carrier strike groups were historically designated carrier battle groups.
  • Carrier air wings were historically designated carrier air groups.

III.ii.2.H.2.c. Echelon for the Naval Surface Force

 The following list shows the echelon for the Naval Surface Force:
  • flagship, and
  • Cruiser Destroyer Group Squadron (CCDG-5; DESRON-23)
Note: The Cruiser Destroyer Group Squadron consists of the Surface Group, Service Group Squadron, Amphibious Group Squadron, Mine Group Division, and Special Warfare Group.

III.ii.2.H.2.d. Echelon for the Naval Submarine Force

 The following list shows the echelon for the Naval Submarine Force:
  • submarine group, and
  • submarine squadron (SUBRON 11)

III.ii.2.H.2.e. Ship Designations

 Individual ships under the above echelons are identified as USS (name of ship) followed by an alpha-numerical hull number which
  • distinguishes the ship from other ships with the same name that may have preceded or may have followed it, and
  • identifies the type of ship.
Example: USS Independence CVA-62.

III.ii.2.H.2.f. Shore Establishment Organization

 Shore establishments, such as non-moveable shore installations, were organized as bureaus (technical in nature) that, with the exception of personnel and medicine and surgery, became the Naval material command in 1963. Other system type commands have followed this tradition.


3. Air Force Organizational Structure

Introduction

 This topic contains information on the Air Force organizational structure, including
  • Air Force echelons and appropriate designations
  • availability of organizational records, and
  • other organizational units that may have created records.

Change Date

 December 13, 2005

III.ii.2.H.3.a. Air Force Echelon and Appropriate Designations

 The table below lists the echelon of Air Force units and appropriate designations.
UnitsDesignations
Command Geographical/specified mission
Air force Numerical/geographical
Air Division Numerical
Wing Numerical/specified mission
Group Numerical/specified mission
Squadron Numerical/specified mission/alpha
Flight Numerical—Alpha

III.ii.2.H.3.b. Availability of Organizational Records

 Other organizational records may be available, such as
  • medical records
  • rosters
  • morning reports
  • courts martial, and
  • academic records.
Notes:
  • Some records may have a limited retention period.
  • Academic records dated after 1967 may be obtained from another National Archives and Records Administration center, if still retained.
  • Morning reports were discontinued in June 1966.

III.ii.2.H.3.c. Other Organizational Units That May Have Created Records

 Records, including clinical and medical records, may exist for other organizations and units, such as
  • agency center
  • hospital
  • office
  • service, and
  • academy.


4. Marine Corps Organizational Structure

Introduction

 This topic contains information on the Marine Corps organizational structure, including
  • Marine Corps echelons and appropriate designations
  • division echelons, and
  • availability of organizational records.

Change Date

 January 5, 2017

III.ii.2.H.4.a. Marine Corps Echelons and Appropriate Designations

 The table below lists the Marine Corps echelons and appropriate designations. For clarification, samples of unit designations are shown in italics.
EchelonDesignation
Fleet Marine Force Atlantic/Pacific (FMFPac)
Marine Amphibious Force Note: Consists of the
  • Marine Division
  • Marine Aircraft Wing, and
  • Marine Logistics Group
    • historically, Force Service Support Group, and
    • counterpart, Marine Wing Support Group.
Roman numeral (I MAF) (operational)
Division Note: Major sub-elements consist of
  • regiments, and
  • battalions.
Numerical (3rdMarDiv) Reference: For more information on the echelons of a division, see M21-1, Part III, Subpart ii, 2.H.4.b.
Wing Note: Major sub-elements consist of
  • groups, and
  • squadrons.
Numerical (1stMAW) Note: Squadrons are designated alpha-numerically. (VMA-211; HMM-262)
Marine Expeditionary Force (MEF) Note: Marine Air ground task force for operations and exercises which consists of the
  • Marine Division
  • Marine Aircraft Wing, and
  • Marine Logistics Group.
Roman numeral (III MEF)
Marine Expeditionary Brigade (MEB) Note: Marine Air ground task force for operations and exercises which consists of the
  • Regimental Landing Team
  • Composite Aircraft Group, and
  • Combat Logistics Regiment.
Numerical (3d MEB)
Marine Expeditionary Unit (MEU) Note: Marine Air ground task force for operations and exercises which consists of the
  • Battalion Landing Team
  • Composite Aircraft Squadron, and
  • Combat Logistics Battalion
Numerical (31 MEU)
Notes:
  • Expeditionary units replaced historically designated amphibious units.
  • Logistics units replaced historically designated force service support units.

III.ii.2.H.4.b. Division Echelons

 The table below lists the Marine Corps division echelons and appropriate designations.
EchelonDesignation
Regiment Numerical (7th Marines; 7th Mar.)
Battalion Numerical (2nd Battalion; 2nd Bn)
Company Alpha or phonetic (D Company; Delta Co.)
Platoon Numerical (1st Platoon; 1st Plt.)
Squad Numerical (3rd Squad; 3rd Sqd.)

III.ii.2.H.4.c. Availability of Organizational Records

 The organizational records listed below are available for the years shown.
  • Muster rolls are available for the years 1801 through present.
  • Indexes are available for the years 1897 through 1939.
  • Unit diaries are available for the years 1949 through 1964.
  • Bound diaries are available back to 1901.
Notes:
  • Unit diaries have been microfilmed and are stored on the 5th floor of the National Personnel Records Center (NPRC). These unit records may include
    • command chronologies
    • operational situation reports (sitreps), and
    • operation after-action reports.
  • Some individual reels may be unusable due to poor storage conditions.
  • Marine Corps headquarters maintains duplicate copies of the unit diaries.
  • Many Marine Corps unit records are stored on compact discs (CDs) and accessed via the Stressor Verification page.
Reference: For more information on accessing these records, see


5. Guide for Service Numbers 1 through 9,999,999

Introduction

 This topic contains a guide to service numbers 1 through 9,999,999, including
  • Army service numbers
  • Navy service numbers
  • Marine Corps service numbers, and
  • Coast Guard service numbers.

Change Date

July 23, 2018

III.ii.2.H.5.a. Army Service Numbers

 The table below lists the numbers used for Army enlisted personnel for the periods shown. Notes:
  • The Army originally assigned Air Force service numbers lower than 10,000,000.
  • Omitted blocks of numbers were not assigned.
SeriesDates Assigned
1 through 5,999,999 1918 through 1919
6,000,000 through 7,999,999 1919 through 1940
8,000,000 through 8,999,999 1948 and after (for Women only)

III.ii.2.H.5.b. Navy Service Numbers

 The table below lists the numbers used for Navy enlisted personnel for the periods shown.
SeriesDates Assigned
1,000,000 through 1,999,999 1885-1918
2,000,000 through 9,999,999 1918-1965
100,000 and higher (Letter Prefix) 1965 and after

III.ii.2.H.5.c. Marine Corps Service Numbers

 The table below lists the numbers used for Marine Corps enlisted personnel for the periods shown.
SeriesDates Assigned
20,000 through 99,999 1905 through 1917
100,000 through 349,999 1917 through 1941
350,000 through 670,899 1941 through 1947
700,000 through 799,999 reserved for female enlisted personnel only
800,000 through 999,999 1943 through 1947
1,000,000 through 1,699,999 1944 through 1957
1,700,000 through 1,799,999reserved for female enlisted personnel only
1,800,000 through 1,999,999 1956 through 1965
2,000,000 and higher 1964 and after

III.ii.2.H.5.d. Coast Guard Service Numbers

 The table below lists the numbers used for Coast Guard enlisted personnel for the periods shown.
SeriesDates Assigned
100,000 through 199,999 through 1930
200,000 through 254,999 1930 through 1942
255,000 through 349,999 1945 through 1962
350,000 through 499,999 1962 until 1974
500,000 through 999,999 1941 through 1945
2,000,000 through 2,199,999 1948 through 1974

6. Guide for Service Numbers 10,000,000 through 19,999,999

Change Date

December 13, 2005

III.ii.2.H.6.a. Regular Army and Regular Air Force Enlisted Service Numbers

 The table below lists the numbers used for regular Army and regular Air Force enlisted personnel for the periods shown. Notes:
  • Series 10,000,000 through 10,999,999 are used for initial enlistments occurring outside the continental limits.
  • The Army originally assigned Air Force service numbers lower than 10,000,000.
SeriesDates Assigned
10,000,000 through 10,999,999 1940 and after
11,000,000 through 11,142,500 1940 through 1945
11,142,501 through 11,188,000 1946 through 1948
11,188,001 through 11,238,500 1949 through 1951
11,238,501 through 11,283,000 1952 through 1954
11,283,001 through 11,344,500 1955 through 1957
11,344,501 through 11,384,000 1958 through 1960
11,384,001 through 11,999,999 1961 and after
12,000,000 through 12,242,000 1940 through 1945
12,242,001 through 12,321,000 1946 through 1948
12,321,001 through 12,393,500 1949 through 1951
12,393,501 through 12,469,000 1952 through 1954
12,469,001 through 12,553,375 1955 through 1957
12,553,376 through 12,614,900 1958 through 1960
12,614,901 through 12,999,999 1961 and after
13,000,000 through 13,197,500 1940 through 1945
13,197,501 through 13,299,700 1946 through 1948
13,299,701 through 13,408,700 1949 through 1951
13,408,701 through 13,511,500 1952 through 1954
13,511,501 through 13,621,140 1955 through 1957
13,621,141 through 13,705,500 1958 through 1960
13,705,501 through 13,999,999 1961 and after
14,000,000 through 14,204,500 1940 through 1945
14,204,501 through 14,300,770 1946 through 1948
14,300,771 through 14,454,000 1949 through 1951
14,454,001 through 14,547,500 1952 through 1954
14,547,501 through 14,661,000 1955 through 1957
14,661,001 through 14,745,000 1958 through 1960
14,745,001 through 14,999,999 1961 and after
15,000,000 through 15,201,000 1940 through 1945
15,201,001 through 15,280,500 1946 through 1948
15,280,501 through 15,465,760 1949 through 1951
15,465,761 through 15,530,600 1952 through 1954
15,530,601 through 15,593,615 1955 through 1957
15,593,616 through 15,639,615 1958 through 1960
15,639,616 through 15,999,999 1961 and after
16,000,000 through 16,201,500 1940 through 1945
16,201,501 through 16,307,000 1946 through 1948
16,307,001 through 16,398,890 1949 through 1951
16,398,891 through 16,481,925 1952 through 1954
16,481,926 through 16,600,497 1955 through 1957
16,600,498 through 16,638,100 1958 through 1960
16,683,101 through 16,999,999 1961 and after
17,000,000 through 17,183,500 1940 through 1945
17,183,501 through 17,254,500 1946 through 1948
17,254,501 through 17,338,810 1949 through 1951
17,338,841 through 17,410,300 1952 through 1954
17,410,301 through 17,512,785 1955 through 1957
17,512,786 through 17,592,940 1958 through 1960
17,592,941 through 17,999,999 1961 and after
18,000,000 through 18,247,100 1940 through 1945
18,247,101 through 18,360,800 1946
18,360,801 through 18,546,000 1947 through 1957
18,546,001 through 18,607,725 1958 through 1960
18,607,726 through 18,999,999 1961 and after
19,000,000 through 19,235,500 1940 through 1945
19,235,501 through 19,324,485 1946 through 1948
19,324,486 through 19,420,000 1949 through 1951
19,420,001 through 19,520,770 1952 through 1954
19,520,771 through 19,590,665 1955 through 1957
19,590,666 through 19,597,661 1958
19,597,662 through 19,999,999 1959 and after

7. Guide for Service Numbers 20,000,000 and Higher

Change Date

December 13, 2005

III.ii.2.H.7.a. Service Numbers 20,000,000 and Higher

 The table below lists the service numbers 20,000,000 and higher, the time periods in which they were issued, and the service categories to which they were issued.

Series

Period Issued

Service Category

20,000,000 through 20,999,999 1940 through 1946 Enlisted National Guard in active duty.
21,000,000 through 29,999,999 1946 and after Enlisted National Guard of the U.S.
30,000,000 through 39,999,999 1940 through 1946 Enlisted personnel inducted into the Army of the U.S.
40,000,000 through 41,999,999 --- Apparently not used or allocated.
42,000,000 through 46,999,999 1943 through 1946 Enlisted personnel inducted into the Army of the U.S.
47,000,000 through 49,999,999 --- Apparently not used or allocated.
50,000,000 through 59,999,999 1948 through 1966 Army and Air Force Emergency Interim Issue (EM). Note: Regular Army and Air Force are not included.
60,000,000 through 69,999,999 1966 and after Army and Air Force EM. Note: Regular Army and Air Force are not included.
70,000,000 through 89,999,999 --- Apparently not used or allocated.
90,000,000 through 99,999,999 1940 through 1945 Only a limited number, about 20,000 within this series, were used for the Philippine Army during World War II. Note: There is no evidence of other usage.

Source: VA M21-1 Adjudication Procedures Manual, M21-1, Part III, Subpart ii, Chapter 2, Section H (U.S. government work, reproduced for reference). Browse all sections →