Roles in the Corps

There are hundreds of ways to serve, and every Marine trains in an area of expertise that contributes to the success of our missions.
Whatever their expertise or field of training, Marines are ready to transition from mission to mission at a moment's notice.


The Field Artillery occupational field is divided into three areas of responsibility: the firing battery, field artillery operations and artillery observation/liaison. Marines assigned to a firing battery are responsible for moving, loading, firing, protecting and maintaining the cannon weapon systems. Marines assigned to the operations section maintain the equipment for finding targets and relaying the data to the firing battery. Observation/liaison Marines direct artillery and naval gunfire in support of the infantry.

Initial Training

After recruit training, Field Artillery Marines receive training specific to their military occupational specialty at Fort Sill, OK.

Within the MEU

An artillery battery is made up of six 155-millimeter howitzers and provides fire support for Marine infantry and armor. Seven-ton trucks are used to move the artillery pieces, and additional trucks provide support and ammunition.

Specialties in Artillery include:
  • Fire Support Marine: Operates laser designators, range finders and radar beacons for coordinating fire support.
  • Artillery Meteorological Marine: Assists in delivering accurate artillery fire by observing, computing and distributing weather conditions.
  • High Mobility Artillery Rocket System (HIMARS) Operator: Inspects and prepares the HIMARS for movement, combat and firing.


MAGTF refers to the unique four-part structure that organizes Marine Corps operating forces. This framework brings together Aviation, Ground and Logistics Combat elements under a central Command element. The result is a flexible, combined-arms unit with the capabilities to conduct the Marine Corps' full range of operations, from humanitarian aid and disaster relief to projection of power from the sea. 

Many Roles. One Mission.

The Marine Corps is only as capable as each and every Marine. That's why all Marines have a specific role for which they are optimally trained, in support of the overall mission.



A MEU, or Marine Expeditionary Unit, is the smallest type of MAGTF, often providing the most substantial response in the shortest amount of time. 2,200 Marines that are trained in hundreds of areas of expertise serve on a MEU. Here is the breakdown of a MEU's makeup:

Command Element – Approximately 200 Marines. Responsible for command and control of the entire MEU.

Ground Combat Element – Approximately 1,200 Marines. A Battalion Landing Team that includes three rifle companies, a weapons company, a battery of artillery and platoons of the following: combat engineers, light armored reconnaissance, tanks, Force Reconnaissance and amphibious assault vehicles.

Aviation Combat Element – Approximately 500 Marines. A MEU's ACE is built around a medium tilt-rotor squadron, reinforced by CH-53E heavy lift helicopters, light attack helicopters and Harrier attack jets. The result is a squadron of 25 to 30 aircraft.

Logistics Combat Element – Approximately 300 Marines. Provides supply, transportation, maintenance and additional support for the MEU.


MEUs deploy aboard an Amphibious Ready Group (ARG): Three naval ships specifically designed to provide the Marines with a mobile base of operations. See here what serving aboard a MEU entails.