Defense Primer: The Military Departments

Defense Primer: The Military Departments

Updated January 9, 2023
Defense Primer: The Military Departments
Military Departments
department reporting to a secretary include the under
The term military department refers to the executive
secretary, assistant secretaries, and general counsel. These
functions of an armed service and the service’s activities,
officials also are appointed by the President with the advice
installations, and field headquarters, all of which are under
and consent of the Senate. Specific areas of responsibility
the control and direction of the secretary of the department
for the assistant secretaries include logistics, manpower,
(10 U.S.C. §101(a)(6)). There are three federal military
acquisition, and financial management.
departments and they are within the Department of Defense
Armed Services
(DOD): the Department of the Army, the Department of the
A military department contains at least one armed service.
Navy, and the Department of the Air Force. A military
The President appoints a four-star general or admiral in an
department prepares and provides strategic, conventional,
armed service as its service chief for four years with the
and special operations forces for military operations
advice and consent of the Senate. A service chief reports to
conducted by DOD (see Figure 1).
the secretary of the department and is responsible for the
Figure 1. Typical Structure of Military Departments
activities, personnel, and operations of the service. The
service chiefs in the military departments also are members
Secretary of the Military Department
of the Joint Chiefs of Staff in DOD. Each armed service has
Office of the Secretary
a service staff with the principal role of assisting the service
chief and the office of the secretary of the department. The
Service Chief or Chiefs
secretary of the department determines the duties, titles, and
membership of a service staff, unless prescribed by law.
Service Staff or Staffs
Military Law
Armed Service or Services
A criminal justice system for servicemembers established
Source: CRS analysis of military department statutory authorities.
under the Uniform Code of Military Justice (UCMJ) applies to
the military departments. Active duty servicemembers and
There is an executive headquarters in each military
regular component military retirees are subject to the
department for administering its activities, personnel, and
punitive measures in the UCMJ at all times and in any place.
organizations. The type and number of personnel permitted
Military law is meant to promote justice, efficiency, and
to work in an executive headquarters are limited by law and
discipline in the armed services. It is exercised primarily in a
differ among the three departments (see Table 1).
judicial forum known as a court-martial or an administrative
forum known as a non-judicial punishment proceeding.
Table 1. Executive Headquarters Personnel Limits
Each armed service usually comprises both active and
Generals/
Other
Civilian
Total
reserve forces. The Army is composed of the Regular
Admirals
Officers
Employees
Army, Army Reserve, and Army National Guard of the
United States. The Navy is composed of the Regular Navy,
Department of the Army
Navy Reserve, and Fleet Reserve. The Marine Corps is
67
1,833
1,350
3,250
composed of the Regular Marine Corps, Marine Corps
Reserve, and Fleet Marine Corps Reserve. The Air Force is
Department of the Navy
composed of the Regular Air Force, Air Force Reserve, and
Air National Guard of the United States. The Space Force
74
1,726
1,350
3,150
contains the Regular Space Force.
Department of the Air Force
U.S. Coast Guard
The Coast Guard is the only armed service not in a military
60
1,590
1,100
2,750
department, as it operates under the Secretary of Homeland
Source: 10 U.S.C. §§7014(f), 8014(f), 9014(f).
Security; however, during war or by the direction of the
Note: Personnel limits do not apply in time of war and may be
President, the Coast Guard operates under the Secretary of
increased by 15 percent of such limits in time of national emergency.
the Navy as a naval force. The Coast Guard has a service chief
and a service staff, and is composed of the Regular Coast
Each military department is led by a civilian secretary
Guard, Coast Guard Reserve, and Coast Guard Auxiliary.
whom the President of the United States appoints with the
advice and consent of the U.S. Senate. The authority of a
Department of the Army
secretary runs from the President through the Secretary of
The Office of the Secretary of the Army administers the
Defense. A secretary of a military department is responsible
Department of the Army; secretarial authorities are set forth
for training, equipping, and organizing the armed service or
in 10 U.S.C. §7013. The department’s armed service is the
services of the department. Principal officials of the
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Defense Primer: The Military Departments
Army, which is the principal land force of the United
Table 4. Department of the Air Force Personnel
States. The department’s fiscal year (FY) 2023 budget
request was approximately $177.5B, an increase of $2.8B
FY-2021
FY-2022
FY-2023
Category
over the appropriations enacted for FY 2022. The number
Actual
Estimate
Estimate
of personnel in the department is included in Table 2.
Active Duty Air
328,071
328,300
323,400
Force
Table 2. Department of the Army Personnel
Active Duty Space
FY-2021
FY-2022
FY-2023
6,563
8,400
8,600
Category
Force
Actual
Estimate Estimate
Air National Guard
108,483
108,300
108,400
Active Duty Army
486,490
485,000
473,000
Air Force Reserve
70,570
70,300
70,000
Army National Guard
337,525
336,000
336,000
Air Force Civilian
175,162
177,816
179,690
Army Reserve
184,358
189,500
189,500
Space Force Civilian
1,009
4,548
4,920
Army Civilian
199,472
196,111
196,897
Total
689,585
697,664
695,010
Total
1,207,845
1,206,611
1,195,397
Source: DOD, Defense Manpower Profile Report – Fiscal Year 2023,
Source: DOD, Defense Manpower Profile Report – Fiscal Year 2023,
September 27, 2022, pp. 2-3.
September 27, 2022, pp. 2-3.
Uniformed Services
Department of the Navy
The armed services are six of the eight uniformed services
The Office of the Secretary of the Navy administers the
of the United States (10 U.S.C. §101(a)(4)-(5)). Although
Department of the Navy; secretarial authorities are set forth
they are not armed services, the two remaining uniformed
in 10 U.S.C. §8013. The department’s armed services are
services have contingent roles in the military departments
the Navy and the Marine Corps, which are the principal
during war or by the direction of the President.
naval forces of the United States. The department’s FY
2023 budget request was approximately $230.8B, an
Public Health Service
increase of $9.1B over the appropriations enacted for FY
The commissioned corps of the Public Health Service (PHS
2022. The number of personnel in the department is
Corps) in the Department of Health and Human Services
included in Table 3.
(HHS) is a uniformed service subject to the control and
direction of the Secretary of HHS. The Assistant Secretary
Table 3. Department of the Navy Personnel
for Health within HHS is the uniformed administrator of the
FY-2021
FY-2022
FY-2023
Public Health Service (PHS) and is appointed as a four-star
Category
Actual
Estimate
Estimate
officer. If transferred to DOD, PHS Corps would become a
branch of the armed services (42 U.S.C. §217). The PHS
Active Duty Navy
347,895
347,441
346,300
Corps is composed of a Regular Corps and Ready Reserve
Corps and has a uniformed director who is appointed as a
Active Duty Marine
179,678
177,249
177,000
three-star officer and serves as the Surgeon General.
Corps
National Oceanic and Atmospheric Administration
Navy Reserve
47,491
47,186
47,623
The commissioned corps of the National Oceanic and
Marine Corps
Atmospheric Administration (NOAA Corps) in the
35,240
32,357
33,000
Reserve
Department of Commerce is a uniformed service subject to
the control and direction of the Secretary of Commerce. If
Navy Civilian
200,872
201,810
203,222
transferred to DOD, NOAA Corps would become part of a
Marine Civilian
22,483
22,470
22,486
military department (33 U.S.C. §3061). The NOAA Corps
contains only active duty commissioned officers and has a
Total
833,659
828,513
829,631
uniformed director who is appointed as a three-star officer
Source: DOD, Defense Manpower Profile Report – Fiscal Year 2023,
and serves as a vice-admiral.
September 27, 2022, pp. 2-3.
Related CRS Publication
Department of the Air Force
CRS In Focus IF10543, Defense Primer: The Department of
The Office of the Secretary of the Air Force administers the
Defense, coordinated by Nathan J. Lucas
Department of the Air Force; secretarial authorities are set
forth in 10 U.S.C. §9013. The department’s armed services

are the Air Force and the Space Force, which are the
principal aerospace forces of the United States. The
Alan Ott, Analyst in Defense and Intelligence Personnel
department’s FY 2023 budget request was approximately
Policy
$194.0B, an increase of $20.2B over the appropriations
IF10550
enacted for FY 2022. The number of personnel in the
department is included in Table 4.
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Defense Primer: The Military Departments

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