Overview

Article I, Section 8, of the Constitution stipulates, "The Congress shall have Power To ... raise and support Armies ... make Rules for the Government and Regulation of the land and naval Forces ... for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions." The Army's purpose is described in 10 U.S.C. §7062:

It is the intent of Congress to provide an Army that is capable, in conjunction with the other armed forces, of—

(1) preserving the peace and security, and providing for the defense, of the United States, the Commonwealths and possessions, and any areas occupied by the United States;

(2) supporting the national policies;

(3) implementing the national objectives; and

(4) overcoming any nations responsible for aggressive acts that imperil the peace and security of the United States.

The Department of the Army (DA) is one of three military departments, along with the Navy and the Air Force, reporting to the Department of Defense (DOD), which is "using a secondary Department of War designation" under Executive Order (EO) 14347 of September 5, 2025.

Army Composition

The Army is composed of two distinct components: the active component (AC) and the reserve component (RC). RCs are the United States Army Reserve (USAR) and the Army National Guard (ARNG). The department's Army Civilians (DAC) also play a significant supporting role. See Table 1.

The Regular Army is the full-time, federal force of AC soldiers.
USAR is a federal reserve force that provides specialized units and capabilities, as well as individual soldiers when mobilized.
ARNG is a dual-status force that normally remains under the command of state governors and can respond to domestic emergencies, unless its units are mobilized for a federal mission.
DAC are federal government employees who fill a variety of support roles.

Table 1. Army Components

Component	Total Number	Location (CONUS / OCONUS)
AC	455, 397	398,860 / 56,537
USAR	171,321	163,491 / 7,830
ARNG	329,506	318,362 / 11,144
DAC	191,675	182,409 / 9,266

Source: Defense Manpower Data Center, as of August 31, 2026, accessed November 2, 2026. Numbers are updated quarterly.

Note: CONUS = Continental United States and OCONUS = Outside of the Continental United States (overseas).

Army Senior Leadership

The DA is led by a civilian Secretary of the Army appointed by the President with the advice and consent of the Senate. The Secretary of the Army reports to the Secretary of Defense, who is using "Secretary of War" as a "secondary title" under EO 14347 of September 5, 2025, and serves as civilian oversight for the Army as an institution and the Chief of Staff of the Army (CSA). The CSA is an administrative position held by a four-star Army general and is a statutory office (10 U.S.C. §7033). The CSA is the chief military advisor and deputy to the Secretary of the Army and, by statute (10 U.S.C. §151), serves as a member of the Joint Chiefs of Staff (JCS). The JCS is composed of DOD's senior uniformed leaders who advise the President, Secretary of Defense, and Cabinet officials on military issues.

Command Authority

The authorities of the Secretary of the Army and the CSA are prescribed by law: 10 U.S.C. §7013 and 10 U.S.C. §7033, respectively. The CSA does not have operational command authority over deployed Army units. Under 10 U.S.C. §162, the operational chain of command runs from the President to the Secretary of Defense and then to the commanders of the unified combatant commands, with the Chairman of the JCS (CJCS) serving as the principal military advisor rather than a commander of forces. The CSA does, however, exercise supervision of Army units and organizations as designated by the Secretary of the Army. Under 10 U.S.C. §7074, the Secretary of the Army has authority to divide the Army into subordinate commands and organizations to accomplish the Army's mission.

Operational and Institutional Missions

According to the Army,

[t]he operational Army consists of numbered armies, corps, divisions, brigades, and battalions that conduct full-spectrum operations around the world. The institutional Army supports the operational Army. Institutional organizations provide the infrastructure necessary to raise, train, equip, deploy, and ensure the readiness of all Army forces.

The operational Army, known as the Operational Force, consists of

units that are trained, equipped, and ready to deploy. These forces make up about two-thirds of the Regular Army and three-fourths of the Total Army.

The institutional Army supports the operational Army by

generating, preparing, and sustaining the Army operating forces. Institutional forces do not normally deploy, but they perform other critical tasks like recruiting, servicing, educating, mobilizing, and constructing.

Army Command Structure

There are three types of commands: Army Commands, Army Service Component Commands (ASCCs), and Direct Reporting Units (DRUs).

Army Commands

Army commands perform many Title 10 functions across multiple disciplines. At present, the two Army Commands include the Army Material Command (AMC), which provides technology, acquisition, and logistics support to the Army, and the U.S. Army Transformation and Training Command (T2COM), which generates, develops, designs, and trains Army forces.

New U.S. Army Futures and Autonomous Systems Command (FASCOM)

On October 1, 2026, the Acting Secretary of the Army directed the establishment of FASCOM. FASCOM is to be a three-star headquarters and expected to focus on autonomy in the areas of aviation, armor, fires, sustainment, engineering, and training.

Army Service Component Commands (ASCCs)

ASCCs are "operational-level organizations that serve as the primary Army components for combatant commanders throughout the different geographical commands." The ASCC commander is responsible for advising the combatant commander on the allocation and employment of Army forces assigned to the combatant command. There are eight ASCCs:

U.S. Army Central (USARCENT). Provides oversight and control of Army operations throughout the U.S. Central Command (USCENTCOM) Area of Responsibility (AOR).
U.S. Army Europe and Africa (USAREUR–AF). Provides oversight and control of Army operations throughout the U.S. European Command (USEUCOM) and U.S. Africa Command (USAFRICOM) AOR.
U.S. Army Pacific (USARPAC). Provides oversight and control of Army operations throughout the U.S. Pacific Command (USPACOM).
U.S. Army Western Hemisphere Command (USAWHC). Theater Army for the U.S. Northern Command (USNORTHCOM) and U.S. Southern Command (USSOUTHCOM).
U.S. Army Cyber Command (USARCYBER). Directs and conducts Army integrated electronic warfare, cyberspace, and information operations.
U.S. Army Transportation Command (ARTRANS). ASCC to the U.S. Transportation Command (USTRANSCOM) and a major subordinate command to the AMC.
U.S. Army Space and Missile Defense Command (USASMDC). ASCC to the U.S Space Command (USSPACECOM) and the U.S Strategic Command (USSTRATCOM) and supports USNORTHCOM by defending against ballistic missile attack.
U.S. Army Special Operations Command (USASOC). ASCC to the U.S. Special Operations Command (USSOCOM).

Direct Reporting Units (DRUs)

DRUs have institutional or operational functions and provide broad, general support to the Army. According to the Army, the 13 DRUs include