https://crsreports.congress.gov
Updated November 21, 2022
Defense Primer: Organization of U.S. Ground Forces
Overview
The Army is the U.S. military’s primary ground force. Title
10, Subtitle B, Part I, Chapter 307 of the U.S. Code
addresses the organization of the Army. The Marine Corps
serves as the Navy’s ground-focused fighting force. Title
10, Subtitle C, Part I, Chapter 507, Section 5063 addresses
Marine Corps composition and functions.
Organizational Levels of U.S. Ground
Forces
The Congressional Budget Office’s (CBO’s) The U.S.
Military’s Force Structure: A Primer, 2021 Update notes:
The Army and Marine Corps are generally
organized as hierarchies of units, with each type of
unit commanded by a noncommissioned or
commissioned officer of a specific rank. These units
are described from smallest to largest.
Squad/Team/Section. A squad is led by a sergeant and
consists of 4-12 personnel. Squads can be further divided
into teams or sections.
Platoon. A platoon—led (Army) or commanded (Marines)
by a lieutenant and includes varying numbers of
subordinate squads, teams, or sections—may vary from 16
to 50 personnel. Heavy platoons have armored vehicles,
such as tanks or infantry fighting vehicles, depending on
platoon type.
Company/Troop/Battery. A company is commanded by a
captain and includes two to five subordinate platoons
(usually three or four). It has about 60-200 personnel.
Cavalry (air or ground) companies are called troops (Army
only); artillery and air and missile defense companies are
called batteries.
Battalion/Squadron. A battalion is commanded by a
lieutenant colonel and usually includes three to five combat
companies and a support company. It has about 400-1,000
personnel. Cavalry battalions are called squadrons.
Brigade Combat Team/Support
Brigades/Regiment/Group. Army brigades are
commanded by a colonel and generally are configured as a
brigade combat team (BCT) or a support brigade. A BCT
has about 4,000-4,700 personnel, depending on type. Army
cavalry brigades are called regiments; some types of
support brigades are called groups. Marine Corps units at
this level also are called regiments. (The term Marine
Expeditionary Brigade [MEB] refers to a regimental-size
task force, which is larger than an Army Brigade Combat
Team [BCT]).
Division. An Army division is commanded by a major
general and includes two to five BCTs (usually four), an
aviation brigade, an artillery brigade, an engineer brigade,
and a logistics brigade. Army divisions consist of 12,000-
16,000 personnel. Marine divisions, also commanded by
major generals, consist of three regiments and supporting
units, and consist of about 6,600 personnel.
Corps. Corps are commanded by a lieutenant general and
include two to five divisions and numerous support
brigades and commands. Corps have about 40,000-100,000
personnel. The Marines do not have designated corps,
although a Marine Expeditionary Force (MEF) is similar in
size and also is commanded by a lieutenant general.
Army. An army is the highest command level in a given
theater of operations and typically has 100,000-300,000
personnel. It is an element of a joint command structure,
with the Army’s component commanded by a general. An
Army’s operational theater is established to support one or
more corps and includes numerous support brigades and
support commands.
Army Brigades
According to The U.S. Military’s Force Structure: A
Primer, 2021 Update, Army brigades are organized as
follows.
The Brigade Combat Team (BCT) is the basic combined-
arms building block of the Army. It is a permanent, stand-alone,
self-sufficient, and standardized tactical force of about 4,000
soldiers. At present, the Army has 58 BCTs, with 31 BCTs in
the Regular Army (RA) and 27 BCTs in the Army National
Guard (ARNG).
The Army has three types of BCTs: Infantry BCTs (IBCTs),
Armored BCTs (ABCTs), and Stryker BCTs (SBCTs).
Infantry BCTs (IBCTs) include three infantry battalions, a
reconnaissance and surveillance cavalry squadron, a field artillery
battalion, a brigade engineer battalion, and a logistics support
battalion. IBCTs also are organized to be airborne or air-assault
capable. The Army currently has 13 Active Component and 20
National Guard IBCTs.
Armored BCTs (ABCTs) include three armor/mechanized
infantry battalions, an armed reconnaissance cavalry squadron, a
field artillery battalion, a logistics support battalion, and a brigade
engineer battalion. The Army currently has 11 Active
Component and 5 National Guard ABCTs.
Stryker BCTs (SBCTs) are equipped with the Stryker, an
eight-wheel-drive armored vehicle. SBCTs consist of three
infantry battalions, a cavalry squadron for reconnaissance and
target acquisition, a field artillery battalion, a brigade support
battalion, a brigade engineer battalion, a military intelligence
company, an engineer company, a signal company, an antitank
company, and a headquarters company. The Army currently has
7 Active Component and 2 National Guard SBCTs.
