Military Occupational Specialty

A Military Occupational Specialty (MOS) is a job classification in use in the U. S. Army and the U. S. Marine Corps.

In the U. S. Air Force, a system of Air Force Specialty Codes (AFSC) is used. In the U. S. Navy, a system of Naval ratings and designators is used.

The occupational specialty system uses a system of letters and numbers to identify general and specific jobs of military personnel. Different branches of the military use different alphanumeric systems, but all differentiate between Comparative military ranks (enlisted personnel), warrant officers, and commissioned officers.


Army MOS

NOTE: The U. S. Army is currently restructuring its designations. Major changes have been made and will continue to be made into 2007.

For more information, please see the List of U. S. Army MOS.

Enlisted personnel

The U. S. Army separates occupational specialties into "Occupational Fields" ranging from 11 to 98 (Infantry to Communications Intelligence). Inside of the Occupational Field designation, it lists pertinent MOS codes in a 3-digit alphanumeric system. For example, in the Occupational Field 31 (Law Enforcement) there are 3 MOS codes: 31B (Military Police), 31D (Criminal Investigation Special Agent), and 31E (Corrections Specialist).

Within each MOS, there is a ranking of "Skill Levels". These designate the different jobs that are assigned with rank in that MOS. For example, in the 31B (Military Police) MOS, there are 5 Skill Levels ranging from #1 (team member - most junior) to #5 (Staff supervision, Planning - most senior).

Commissioned Officers

In regards to Commissioned Officers, occupational codes are structured a bit differently. A new Army officer first receives his/her "Career Branch". This is similar to the Occupational Fields of the enlisted personnel. They range from 11 to 68 (Infantry to Medical Service Corps). Inside of their Occupational Field, there are usually several codes available. For example, in Field 12 (Armor) there are 3 specialties available: 12A (Armor, General), 12B (Armor), and 12C (Cavalry). After an Officer's fifth or sixth year of service, he/she will receive a "Functional Area" designation. More broad than a "Career Branch", this is a general skill set that the Officer is proficient in. For example, an Artillery Officer who has had schooling in communications and public speaking could end up with a Functional Area in Public Affairs (designated number 46).

Marine Corps MOS

The U. S. Marine Corps begins by separating all jobs into "occupational fields" (OccFld), in which no distinction is made between officers and enlisted Marines. The fields are numbered from 01 to 99 and include general categories (Infantry, Logistics, Public Affairs, Ordnance, etc.) that specific jobs fall under.

Each field contains multiple MOS's, each designated by a four-digit numerical indicator and a job title. For example, the infantry field (03) has seven enlisted classifications: Rifleman (MOS 0311), LAV Crewman (MOS 0313), Reconnaissance Man (MOS 0321), Mortarman (MOS 0341), Assaultman (MOS 0351), Antitank Assault Guided Missileman (MOS 0352), and Infantry Unit Leader (MOS 0369).

Each of the jobs have authorized ranks associated with them. For example, anyone raking from Private to Sergeant can be a Rifleman (0311), but only Marines ranking from Staff Sergeant to Master Gunnery Sergeant can be an Infantry Unit Leader (0369).

Duties and tasks are identified by rank because the Marine Corps MOS system is designed around the belief that increased duties and tasks accompany promotions. The first two digits designate the field and, the last two digits identify the promotional channel and specialty. For example, the MOS 0311 indicates that it is in Occupational Field 03 (Infantry) and designates the "Rifleman" (11) MOS. For warrant officers, the MOS 2305 indicates that it is in Occupational Field 23 (Ammunition and Explosive Ordnance Disposal) and designates the "Explosive Ordnance Disposal Officer" (05) MOS. For officers, the MOS 0802 idicates that it is in Occupational Field 08 (Field Artillery) and designates the "Field Artillery Officer" (02) MOS.

Navy Occupational Specialties

The U.S. Navy divides their occupational specialties into ratings for enlisted personnel and designators for officers.

Enlisted Personnel Ratings

The U.S. Navy indicates its "Ratings" by a two or three character code based on the actual name of the rating. These range from from ABE (Aviation Boatswain's Mate - Equipment) to YN (Yeoman). Each Sailor and Chief Petty Officer wears a rating badge indicating their rating as part of their their rate (rank) insignia on full dress and service dress uniforms. The U.S. Coast Guard uses an enlisted rating system nearly identical to the Navy's. For additional information, please see the List of U. S. Navy Ratings.

Commissioned Officer Designators

Officers in the Navy have a designator. It is similar to an MOS but is less complicated and has fewer categories. For example a Surface Warfare Officer with a regular commission has a designator of 1160; a reserve officer would have an 1165 designator. A reserve surface warfare officer specializing in Nuclear training (ie: Engineer on a carrier) would have a designator of 1165N. Navy officers also have one or more 3-character Additional Qualification Designators (AQD) that reflect completion of requirements qualifying them in a specific warfare area or other specialization; in some senses this functions more like the MOS in other services. An officer with the Naval Aviator designator of 1310 might have an AQD of DV3, SH-60F carrier anti-submarine warfare helicopter pilot, or DB4, F-14 fighter pilot. An officer designated 2100, Medical Corps Officer (physician) may hold an AQD of 6CM, Trauma Surgeon, or 6AE, Flight Surgeon who is also a Naval Aviator. Some AQDs may be held by officers in any designator, such as BT2, Freefall Parachutist, or BS1, Shipboard Tomahawk Strike Officer. Navy officer designators and AQD codes may be found in NAVPERS 15839I, The Manual of Navy Officer Manpower and Personnel Classification.

See also

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