The Marines use the Military Occupational Specialty (MOS) Code to identify all the jobs in the Marine Corps. It’s a four-digit code to identify specific job specialties. MOSs are grouped into different occupational fields (the first two digits) and then by a specific job in that field (the last two digits).
After a recruit graduates from boot camp, they’ll get their first job – their primary marine occupational specialty (PMOS). They then head to advanced training. During their career, they may get an additional MOS (AMOS) or a category II MOS, which indicates special skills or duties performed on tours or in training programs.
U.S. Marine Corps Enlisted MOS
The Marines have over 180 enlisted MOSs that are made up of four digits. The Marine Corps MOS structure is not as detailed as the Air Force AFSC. Let’s take a look at MOS 0121 and break it down for you:
0121 – Personnel Clerk
The first two digits tell you that it is a job in MOS (01), Personnel and Administration. The second two digits tell you the exact job – Personnel Clerk.
A Guide to All Marine Enlisted MOSs
Here are the different occupational fields for enlisted Marines:
- 01 – Personnel and Administration
Jobs in this field involve administrative, managerial and technical tasks. Marines are trained in clerical and administrative procedures, office management, personal computer skills, handling military publications and correspondence, preparing orders and directives and using filing systems and record keeping.
- 02 – Intelligence
Marines in this fieldwork with classified information, including gathering and processing it. Jobs include counterintelligence and image interpretation.
- 03 – Infantry
Infantry is the combat arms branch of the Marine Corps. Marines in this field are trained to locate, close in and destroy the enemy by fire and maneuver. They also repel an enemy’s assault by fire and close combat.
- 04 – Logistics
Marines in this field are responsible for providing general and direct support of the Marine Air-Ground Task Force (MAGTF). They may also support the MAGTF during assaults and operations onshore.
- 05 – Marine Air-Ground Task Force (MAGT) Plans
This field is made up of Marines, planning specialists, information operations specialists and security forces advisors.
- 06 – Communications
Marines in the communications field design, install, connect and operate communication networks and information systems. They also do preventative maintenance on computer systems, radio, telephones, cryptography software and hardware systems.
- 08 – Field Artillery
This field has different areas of responsibility. Duties include: firing battery (moving, loading, firing and maintaining cannons); field artillery operations (moving, operating and maintaining equipment that acquires target) and observation and liaison (checking and analyzing combat plans and communicating advice).
- 09 – Training
Jobs in this field include drill, combat, marksmanship, small weapons, water safety, survival and martial arts instructors.
- 11 – Utilities
Those in the utilities field plan and provide utilities to support posts and stations. They establish, operate, maintain and repair power generation units, shower and laundry facilities and HVAC systems
- 13 – Engineer, Construction, Facilities and Equipment
Duties include welding and metalworking. Marines in this field are also responsible for the maintenance, operation and repair of heavy engineering equipment.
- 18 – Amphibious Assault Vehicle
Members of an assault amphibious vehicle (AAV) crew help operate and maintain the vehicle and upgunned weapons stations.
- 21 – Ground Ordnance Maintenance
The ground ordnance maintenance job is to inspect, repair and maintain weapons systems. Tasks include repair analysis, technical inspection, testing of ordnance equipment and quality control.
- 23 – Ammunition and Explosive Ordnance Disposal
There are three positions in this MOS: Basic ammunition and explosive ordnance disposal, ammunition technician and explosive ordnance disposal (EOD) technician.
- 26 – Signals Intelligence/Ground Electronic Warfare
Signals intelligence/ground electronic warfare jobs focus on strategic and tactical intelligence. Marines in this MOS are tasked with monitoring radio and other broadcasts to establish enemy positions. Jobs include signals intelligence analysts, signals intelligence/electronic warfare, cryptanalysts and radio reconnaissance.
- 27 – Linguist
Linguists supervise and participate in translation and interpretation activities to support mission tasks during operations and exercises.
- 28 – Ground Electronics Maintenance
Marines in the ground electronics maintenance MOS install, repair, diagnose and calibrate a wide range of electronic equipment.
- 30 – Supply Administration and Operations
Marines in this MOS perform ground supply administration and operations. Tasks include ordering and processing equipment, maintaining supply warehouses and distributing supplies.
- 31 – Distribution Management
Distribution management involves coordinating travel and shipments by assisting with the transport of military and personal property, helping move marines and their families move between bases. Marines in this MOS also manage the movement of military equipment and supplies.
- 33 – Food Service
Foodservice Marines prepare food for other marines in garrison and the field. They also plan meals to ensure that adequate food is available to Marines working in the field during deployments.
- 34 – Financial Management
The main responsibility of Marines in the financial management MOS is to help budget finances and generate spending estimates. They are also responsible for reconciling and preparing accounting records.
- 35 – Motor Transport
Marines in the motor transport field ensure that all troop and equipment transport vehicles are inspected, maintained and in mission-ready condition. They may also be motor vehicle operators and drive a variety of USMC vehicles.
- 41 – Morale, Welfare and Recreation
Marines in the morale, welfare and recreation MOS are responsible for the well-being of Marine service members and their military families. They work as morale, welfare and recreation (MWR) specialists.
- 44 – Legal Services
Marines who work in the legal services field assist military legal officers. They are trained in understanding military law to help both Marines and civilians.
- 45 – Communication Strategy
Jobs within this field include combat photographer and combat photographer. Members in this field are responsible for researching, planning and creating written and visual communication “in order to build understanding, credibility, and trust with audiences,” according to the Marine Corps website.
- 55 – Music
Marines musicians perform music to support military ceremonies, official functions, community relations and recruiting efforts. They have to audition and be accepted as a Marine musician.
- 57 – Chemical, Biological, Radiological and Nuclear Defense
Marines in this field are responsible for conducting defense against chemical, biological, radiological and nuclear attacks. They issue gas masks and related protective equipment and train Marines in their use.
- 58 – Military Police and Corrections
Military police and corrections specialists support commanders in keeping law and order. They enforce military laws, prevent crimes, investigate offenses and apprehend any offenders.
- 59 – Electronics Maintenance
Electronics maintenance specialists maintain, repair and operate different types of electronic equipment that supports air defense, surveillance, weapons systems, radio communication and air traffic control.
- 60/61/62 – Aircraft Maintenance
Marines in the aircraft maintenance field provide support to the total airframe, power plant and aircraft weapons systems. This field is divided into three areas:
- 60 — primary,
- 61 — helicopters
- 62 — fixed-wing aircraft
- 63/64 – Avionics
Avionics supports aviation weapons systems. Jobs in this field include aircraft avionics technician, communications/navigation systems technician and cryptographic systems technician.
- 65 – Aviation Ordnance
Duties of service members in the aviation ordnance MOS include the maintenance of guns, gun pods, bomb racks, aircraft weapons systems, missile launchers and related support equipment.
- 66 – Aviation Logistics
The duties of Marines who work in aviation logistics include a wide range of network infrastructures, such as aviation supply and aviation information systems maintenance.
- 68 – Meteorology and Oceanography
Those in the meteorology and oceanography field are responsible for collecting, assessing and distributing information applicable to friendly and enemy force strengths and weaknesses, including data on climate and atmosphere.
- 70 – Airfield Services
Duties in airfield services include aircraft equipment recovery and rescue and firefighting.
- 72 – Air Control/Air Support/Anti-Air Warfare/Air Traffic Control
Marines in this MOS operate and manage air command and other functions of the Marine aircraft wing. They might get to be an air control electronics operator or an air traffic controller.
- 73 – Navigation Officer/Enlisted Flight Crews
The job of navigation officers and enlisted flight crews are related to the operations and maintenance of aircraft and helicopters. Available jobs include helicopter specialist and unmanned aircraft system operator.
- 80 – Miscellaneous Requirements MOS
The choice of jobs in this field includes recruiter, security guard and parachutist.
U.S. Marine Corps Officer MOS
The Marine officer MOS is similar to the enlisted MOS and is grouped into different occupational fields (the first two digits) and then by a specific job in that field (the last two digits). Most officers go into their Basic School with a basic MOS, and once they finish the course, they get the advanced MOS.
A Guide to All Marine Officer MOSs
Here are the different occupational fields for Marine Corps officers:
- 01 – Manpower Officer
Manpower officers provide human resource and administrative support and would be responsible for ensuring the right people are in the right jobs.
- 02 – Intelligence Officer
Intelligence officers are trained in one of the following intel disciplines: ground, human source, signals or air intelligence. Once they are promoted to major, all the areas merge, and they become Marine air ground task force (MAGTF) intel officers.
- 03 – Infantry Officer
Marine infantry officers are responsible for training Marines in various ground combat missions, gathering and evaluating intel on enemy forces, developing battle plans and commanding your unit’s use of weapons and equipment.
- 04 – Logistics Officer
This job is critical in planning strategies for units at all levels. You would coordinate the movement of troops and equipment from ship to shore and onto forward operating bases.
- 06 – Communications Officer
The communications officer is the mainstay for command and control of Marine forces. Their job would be to oversee the planning, installation, operation and maintenance of telecommunications and computer systems. They have to quickly establish communications capabilities on the battlefield.
- 08 – Field Artillery Officer
Field artillery officers are responsible for leading Marines in tactics, gunnery and gunline drills. They provide close-fire support for infantry, armored reconnaissance and tank units.
- 13 – Combat Engineer Officer
Combat engineer officers lead Marines in demolition, mine and countermine warfare; obstacle placement; breaching and construction. They work in one of four categories of engineering: \Mmobility, counter mobility, survivability and general engineering.
- 17 – Cyberspace Officer
Cyberspace officers command or assist in commanding a cyberspace operations unit or element. They supervise, direct and provide guidance on all aspects of the employment of cyberspace personnel and systems.
- 18 – Amphibious Assault Vehicle Officer
Amphibious assault vehicle officers would command assault amphibian units and direct AA units on maneuvers, tactical problems and in combat.
- 30 – Ground Supply Officer
Ground supply officers lead and train troops in coordinating equipment and supplies for missions. They supervise the buying and contracting of supplies, manage budgets and develop spending plans.
- 34 – Financial Management Officer
Financial management officers are in charge of all financial issues. These issues include managing budgets and disbursing actions. Their job will be to coordinate military pay and travel, budgeting, accounting and directing internal reviews.
- 44 – Judge Advocate
Marine Corps judge advocates are responsible for advising Marines on legal issues. They need law degrees and would need to be accepted into the judge advocate general’s (JAG) corps program.
- 45 – Communication Strategy and Operations Officer
Communication strategy and operations (CommStrat) officers develop communications plans for national and international audiences. They also advise commanders regarding communication strategy.
- 58 – Military Police Officer
Military police officers provide support to your commanders in all areas of law enforcement. They may provide security and law enforcement support on-base or on deployment.
- 60 – Aviation Maintenance Officer
Aviation maintenance officers oversee Marines who maintain aircraft and aviation equipment. Their job is to make sure all aircraft are ready to fly to support any mission.
- 66 – Aviation Supply Officer
Aviation supply officers make essential decisions about budget, inventory management, deployment, personnel and other support matters. They work in the aviation supply department in one of the Marine Aviation Logistics Squadrons (MALS).
- 72 – Aviation Command and Control Officer
Aviation command and control officers serve in one of these three jobs: Air support control officer, air defense control officer or air traffic control officer. Their main duties would include directing the interception of hostile aircraft, directing the employment of surface-to-air missiles, coordinating air support missions and leading activities associated with air traffic control and airspace management.
- 75 – Pilots and Naval Flight Officers
Pilot and naval flight officers (NFO) fly or operate the weapons and electronic systems on board F/A-18 Hornets, EA-6B Prowlers and other assigned aircraft. The pilot focuses on flying the aircraft, and the NFO focuses on the weapons systems.
Jim spent 22 years on active duty, climbing the ranks from airman basic to a decorated Air Force major. Stationed all over the world, he held many high-level posts, including chief of foreign military sales at the U.S. Embassy in Addis Ababa, Ethiopia. Jim earned his Ph.D. through the Montgomery Era GI Bill and spent 13 years teaching African Studies in Pennsylvania. Jim is also an award-winning travel writer.
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