U.S. Marine Corps Command Structure

The United States Marine Corps (USMC), also referred to as the United States Marines, is the maritime land force service branch of the United States Armed Forces responsible for conducting expeditionary and amphibious operations through combined arms, implementing its own infantry, armor, artillery, aerial and special operations forces. The U.S. Marine Corps (USMC) is authorized by the Department of the Navy, which is spearheaded by the Secretary of the Navy. At the top of the organizational structure is a commissioned officer called the Commandant of the Marine Corps. This person is responsible for organizing, recruiting, and training Marines so that they are command and operation ready The USMC comprises over 180,000 active personnel, as well as a Marine Reserve force of approximately 38,500. It is the fourth largest service branch.

The Marine Corps's organizational chart comprises a wide range of units of all sizes. TogetherWeServed has compiled the most complete directory of U.S. Marine Corps units, reflecting the entire USMC command structure. Each Unit Page on Together We Served contains comprehensive information on Marine Corps Unit History, Citations, Patches, Photos, Reunions and also includes a list of all Together We Served Members who were assigned to this Marine Corps Unit. TWS serves as a virtual military base where Marine Corps Veterans of all eras can share in the camaraderie of other Veterans in a secure military-only environment.

The U.S. Marine Corps falls under the Department of the Navy; however its command structure is similar to the Army's, except it follows the "rule of three" and includes Marine expeditionary forces and aircraft wings. The Marine Corps is divided into four groups: operating forces responsible for actual fighting; command headquarters responsible for leadership; support units that provides logistical support, and the Marine Corps Reserve.

As you browse the Together We Served Unit Directory, you can easily see how the USMC commands are organized. The command elements of the U.S. Marine Corps include:

Fire Team

Includes three Marines and a team leader, usually a corporal.


Typically consists of a rifle squad (several fire teams) and a leader, usually a Sergeant. Other infantry squads may be deployed, e.g. mortars, anti-armor, machine guns etc.


Platoons consist of at least 27 Marines, led by a Lieutenant and a Staff Sergeant. A standard rifle company weapons platoon will have three rifle squads.


A company is led by a Captain and their Executive Officer (usually a Lieutenant). There are at least three, and possibly more platoons in a single Company. Companies also have headquarters elements, with the attendant staff necessary to operate one. A Company is sometimes referred to as a Battery.

Marine Corps Battalion

A Marine Corps Battalion consists of three or more Companies, overseen by an HQ unit. Battalions are generally led by either a Lieutenant-Colonel or Colonel, with a Major supporting as XO.

Marine Regiment

A Marine Regiment is three Battalions, totaling more than 2,000 Marines. A Regiment is always led by an officer of the rank Colonel or higher.

Marine Division

A Marine Division consists of over 6,500 Marines, or three Regiments. It is commanded by a Major-General. There are three main Marine Divisions: one in Camp Pendleton, CA, one in Camp Lejeune, NC, and one in Camp Courtney, Okinawa. A fourth Marine Division, headquartered in New Orleans, LA, is a reserve unit, with elements of it scattered across the US. The leader of these four Marine Divisions is the Commandant.

Additional Subdivisions.

The Aircraft Wings subdivision of the Marine Corps consists of squadrons that command flying and non-flying units of about two dozen aircraft, grouped into three or more squadrons or a complete regiment. The Aircraft Wings are equivalent to a division.