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Updated November 16, 2018
Defense Primer: Department of the Army and Army Command
Structure
Overview
Senior Leadership
Article I, Section 8, Clause 12 of the Constitution stipulates,
The DA is headed by a civilian Secretary of the Army
“The Congress shall have power ... to raise and support
(SECARMY) who is appointed by the President with the
Armies ... make rules for the government and regulation of
advice and consent of the U.S. Senate. The SECARMY
the land and naval forces ... for calling forth the militia to
reports to the Secretary of Defense (SECDEF) and serves as
execute the laws of the Union, suppress insurrections and
civilian oversight for the U.S. Army and Chief of Staff of
repel invasions.”
the Army. The Chief of Staff of the Army (CSA) is an
administrative position at the Pentagon held by a four-star
Constitutional Provision
general in the U.S. Army and is a statutory office (10
Article I, Section 8, Clause 12, known as the Army Clause.
U.S.C. §3033). The CSA is the chief military advisor and
“The Congress shall have Power To ... raise and support
deputy to the SECARMY and serves as a member of the
Armies ... ”
Joint Chiefs of Staff (JCS), also a statutory office (10
Relevant Statutes
U.S.C. § 151). The JCS is composed of the DOD’s senior
uniformed leaders who advise the President, SECDEF, and
Title 10, U.S. Code, Subtitle B, Armed Forces: Army
Cabinet officials as needed on military issues.
Title 32, U.S. Code, National Guard
Operational and Institutional Missions
The Department of the Army (DA) is one of the three
The operational Army—known as the Operational Force—
military departments reporting to the Department of
conducts or directly supports the full spectrum of military
Defense (DOD). The Army’s primary mission is to fight
and win the nation’s
operations and consists of numbered armies, corps,
ground wars. The Army’s mission is
divisions, brigades and battalions (e.g., Brigade Combat
both operational and institutional, and it is composed of
Teams [BCTs], Aviation Brigades, Medical Brigades). The
four distinct components: the regular Active component
majority of the Army is currently based in the continental
(AC), the reserve components of the United States Army
United States (CONUS) relying on forward-stationed and
Reserve (USAR), the Army National Guard (ARNG), and
rotational units outside the continental U.S. (OCONUS) to
Department of the Army civilians (DAC). See Figure 1.
deter potential enemies, defend against aggression if
 The Regular Army is the full-time, federal force of AC
needed, and train allies.
soldiers.

The institutional Army supports the operational Army by
USAR is a federal reserve force that provides specialized
providing the training, education, and logistics necessary
units and capabilities, as well as individual soldiers when
“to raise, train, equip, deploy, and ensure the readiness of
mobilized.
all Army forces.” Army organizations whose primary
 ARNG is a dual-status force that normally remains under
mission is to generate and sustain the Operating Forces
the command of state governors and can respond to
(e.g., U.S. Army Training and Doctrine Command
domestic emergencies, unless its units are mobilized for a
[TRADOC], U.S. Army Materiel Command [AMC], U.S.
federal mission.
Army Intelligence and Security Command [INSCOM]) are

also known as the Generating Force. According to the
DAC are federal government workers who fill a variety of
Army’s website, “Without the institutional Army, the
support roles.
operational Army cannot function. Without the operational
Army, the institutional Army has no purpose.”
Table 1. Army Components

Total
Location
Army Command Structure
Component
Number
(CONUS/OCONUS)
There are three types of commands: Army Commands,
Army Service Components Commands (ASCCs), and
AC
465,262
415,854 / 49,408
Direct Reporting Units (DRUs).
USAR
189,387
183,603 / 5,784
Army Commands. Army commands perform many Title
ARNG
334,459
326,577 / 7,882
10 functions across multiple disciplines. They include U.S.
Army Forces Command, the newly established U.S. Army
DAC
248,624
237,038 / 11,586
Futures Command, U.S. Army Materiel Command, and
Source: Defense Military Manpower Center (DMDC), Military and
U.S. Army Training and Doctrine Command.
Civilian Personnel by Service/Agency by State/Country as of June 30,
2018.
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Defense Primer: Department of the Army and Army Command Structure
Army Service Components Commands (ASCCs).
Test and Evaluation Command; and U.S. Army War
ASCCs are operational organizations that are aligned with
College.
combatant commands. ASCCs supporting geographic
combatant commands include U.S. Army Africa, U.S.
CRS Products
Army Central, U.S. Army Europe, U.S. Army North, U.S.
Army Pacific, and U.S. Army South.
CRS Insight IN10889, Army Futures Command (AFC),
by Andrew Feickert.
ASCCs with a global mission supporting functional
combatant commands include U.S. Army Cyber Command,
CRS In Focus IF10540, Defense Primer: Reserve
U.S. Army Space and Missile Defense Command/U.S.
Forces, by Lawrence Kapp.
Army Strategic Command, U.S. Army Special Operations
Command, and U.S. Army Surface Deployment and
Other Resources
Distribution Command.
Department of the Army, DoD Releases Fiscal Year
Direct Reporting Units (DRUs). DRUs consist of one or
2019 Budget Proposal, February 12, 2018, at
more units that have institutional or operational functions.
https://dod.defense.gov/News/News-Releases/News-
These units provide broad, general support to the Army in a
Release-View/Article/1438798/dod-releases-fiscal-year-
single, unique discipline not available elsewhere in the
2019-budget-proposal/
Army and include U.S. Army Acquisition Support Center;
Arlington National Cemetery; U.S. Army Corps of
Department of the Army Budget Materials at
Engineers; U.S. Army Criminal Investigation Command;
https://www.asafm.army.mil/offices/bu/content.aspx?wh
U.S. Army Human Resources Command; U.S. Army
at=BudgetMaterials
Installation Management Command; U.S. Army
Intelligence and Security Command; U.S. Army Marketing
and Engagement Brigade; U.S. Army Medical Command;

U.S. Military Academy; U.S. Army Military District of
Washington; U.S. Army Reserve Command; U.S. Army
Figure 1. Department of the Army

Source: Association of the United States Army (AUSA), Institute of Land Warfare, Profile of the United States Army, September 2018.

Andrew Feickert, Specialist in Military Ground Forces
IF10544
Barbara Salazar Torreon, Senior Research Librarian

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Defense Primer: Department of the Army and Army Command Structure

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