The United States Marine Corps Military Occupational Specialty (MOS) is a system of categorizing career fields. All enlisted and officer Marines are assigned a four-digit code denoting their primary occupational field and specialty. Additional MOSs may be assigned through a combination of training and/or experience, which may or may not include completion of a formal school and assignment of a formal school code.
Occupational Fields (OccFlds) are identified in the first two digits and represents a grouping of related MOSs. Job codes are identified in the last two digits and represent a specific job within that OccFld.
The USMC now publishes an annual Navy/Marine Corps joint publication (NAVMC) directive in the 1200 Standard Subject Identification Code (SSIC) series to capture changes to the MOS system. Previous versions of MCO 1200.17_ series directives are cancelled, including MCO 1200.17E, the last in the series before beginning the annual NAVMC-type directive series.
On 30 June 2016, the Marine Corps announced the renaming of 19 MOSs with gender-neutral job titles, replacing the word or word-part "man" with the word "Marine" in most. Not all instances of the word or word-part "man" were removed, e.g., 0171 Manpower Information Systems (MIS) Analyst, 0311 Rifleman, 0341 Mortarman.
On 15 October 2020, the Marine Corps announced a structured review of 67 Marine Corps MOSs. This review is part of a larger Marine Corps force redesign initiated in March 2020 which was initiated to help the Corps re-align for the future.
Restrictions on officer MOSs include:
- Restricted officers (limited duty officers and warrant officers) cannot hold non-primary MOSs and will be limited to Primary MOS (PMOS) – Basic MOS (BMOS) matches.
- Colonels are considered fully qualified Marine Air Ground Task Force (MAGTF) Officers and, with the exception of lawyers and MOSs 8059/61 Acquisition Management Professionals, will only hold MOSs 8040, 8041, or 8042 as PMOS. Non-PMOSs will not be associated in current service records with General Officers and Colonels, with the exception of MOSs 822X/824X Foreign Area Officers and Regional Affairs Officers.
- MOSs must be required in sufficient numbers as Billet MOSs (BMOS) in the Total Force Structure Manpower System (TFSMS) to be justified. MOSs with no Table of Organization (T/O) requirement or no inventory are subject to deletion/disapproval.
- MOSs must serve a Human Resources Development Process (HRDP) purpose (establish a skill requirement, manpower planning, manages the forces, manage training, identify special pay billets). MOSs not meeting this criterion will be deemed nonperforming MOSs and subject to deletion/disapproval.
- A single track is limited to a single MOS. Separate MOSs are not appropriate based on grade changes unless merging with other MOSs.
An enlisted applicant (male or female) seeking a Program Enlisted For (PEF) code associated with MOSs 0311, 0313, 0321, 0331, 0341, 0351, 0352, 0811, 0842, 0844, 0847, 0861, 1371, 1812, 1833, 2131, 2141, 2146, 2147, or 7212 must meet certain gender-neutral physical standards. For the Initial Strength Test (IST), the applicant must achieve 3 pull-ups, a 13:30 1.5-mile run, 44 crunches, and 45 ammo can lifts. The MOS Classification Standards based on a recruits final CFT and PFT are: 6 pull-ups, 24:51 3-mile run, 3:12 Maneuver Under Fire Course, 3:26 Movement to Contact Court, and 60 ammo can lifts.
Below are listed the current authorized Marine Corps MOSs, organized by OccFld, then by specific MOS. Most MOSs have specific rank/pay grade requirements and are listed to the right of the MOS title, if applicable (see United States Marine Corps rank insignia), abbreviated from the highest allowed rank to the lowest. Officer ranks are noted as Unrestricted Line Officers[a] (ULOs), Limited Duty Officers[b] (LDOs), and Warrant Officers[c] (WOs). Those MOSs which are no longer being awarded[d] are generally kept active within the Marine's service records to allow Marines to earn a new MOS and to maintain a record of that Marine's previous skills and training over time. All MOSs entered into the Marine Corps Total Force System (MCTFS) electronic service records will populate into DoD manpower databases, and be available upon request to all Marines through their Verification of Military Education and Training (VMET) portal, even when MOSs are merged, deactivated, or deleted from the current NAVMC 1200 bulletin, or from MCTFS.
Note: All listed MOSs are PMOS, unless otherwise specified.
Types of MOSs
There are three categories of MOSs:
- Occupational Fields 01-79 (Regular OccFlds) – Occupational Fields that contain all types of MOSs related to a specific occupational field.
- 80XX (Miscellaneous Requirement MOSs) – These are MOSs that do not fit into a regular OccFld but are used on the Marine Corps Table of Organization (T/O).
- 90XX (Reporting MOS) – These MOSs do not exist on the USMC T/O. They are used to meet Department of Navy and Department of Defense reporting requirements.
There are six types of MOSs, divided into primary MOSs and non-primary MOSs. Primary MOSs are of three types:
- Basic MOS – Entry-level MOSs required for entry-level Marines (both officers and enlisted) or others not yet qualified by initial skills training. In addition, when a Reserve Component (RC) Marine transfers to a new unit and does not possess the MOS required for the billet filled, they will be assigned a Basic MOS as Primary MOS until the completion of required formal school training or is otherwise certified to be MOS qualified, and the previous PMOS will be retained but become an Additional MOS. Promotions for enlisted Marines will be based upon their Basic MOS, or if qualified for a PMOS, then upon their PMOS, never on an AMOS.
- Primary MOS (PMOS) – Used to identify the primary skills and knowledge of a Marine. Only enlisted Marines, Warrant Officers, Chief Warrant Officers, and Limited Duty Officers are promoted in their primary MOS. Changes to an Active Component Marine's PMOS without approval from CMC (MM) and changes to a RC Marine's PMOS without approval from CMC (RA) are not authorized. Promotions for enlisted Marines will be based upon their Basic MOS, or if qualified for a PMOS, then upon their PMOS, never on an AMOS.
- Additional MOS (AMOS) – Any existing PMOS awarded to a Marine who already holds a PMOS. Example: after a lateral move to a new job, a Marine's previous PMOS becomes an AMOS and is normally retained in the Marine's service records for historical purposes and manpower management. Marines are not promoted in an AMOS.
There are also three types of non-PMOSs:
- Necessary (NMOS) – A non-PMOS that has a prerequisite of one or more PMOSs. This MOS identifies a particular skill or training that is in addition to a Marine's PMOS, but can only be filled by a Marine with a specific PMOS. When entered as a requirement into the TFSMS, a billet bearing a Necessary MOS must identify a single associated PMOS even if several PMOSs are acceptable prerequisites.
- Free (FMOS) – Non-PMOS that can be filled by any Marine regardless of Primary MOS. A Free MOS requires skill sets unrelated to primary skills.
- Exception (EMOS) – Non-PMOS that is generally a FMOS, but includes exceptions that require a PMOS.
Reporting MOSs and billet designators are special MOSs:
- Reporting MOSs – designated in the 90XX OccFld, but are not found on any USMC T/O as a requirement to fill any billet. They exist solely to capture skills and training that meet Department of Navy and Department of Defense reporting requirements.
- Billet MOSs (BMOS) – The MOS listed on USMC T/Os for each billet within the organization, usually PMOS, but also NMOS, FMOS, EMOS, or Billet Designators. Some billets will include notes about acceptable alternate MOSs, such as a BMOS of 0402 (Logistics Officer) that notes a 3002 (Supply Officer) is an acceptable staffing substitute for that billet.
- Billet Designators – An FMOS requirement indicator, listed on USMC T/Os as a BMOS that can be filled by any Marine of the appropriate grade that is included in the MOS definition (e.g., MOS 8007 Billet Designator-Unrestricted Ground Officer (I) FMOS). Normally, FMOS as a skill designator cannot be a BMOS in the TFSMS.
Relationship of MOS to promotions
Officers are selected for promotion for their potential to carry out the duties and responsibilities of the next higher grade based upon past performance as indicated in their official military personnel file. Promotions should not be considered a reward for past performance, but as incentive to excel in the next higher grade. Officers are not strictly promoted based upon their MOS; all MOS carried by an officer are considered during the selection board process.
Enlisted Marines are promoted based upon their Basic MOS, or their PMOS if one has been earned, not their AMOS, FMOS, NMOS, or EMOS, although upon consideration by a selection board for promotion to Staff Sergeant (E-6) and above, the Board Members will be able to view evidence of other MOSs in the service records of the Marine.
*The core enlisted infantry MOSs for the USMC are 0311, 0331, 0341, (formerly 0351 until 2021), and 0352; and Marines are trained in these jobs at the School of Infantry. All other infantry jobs are taught in follow-on courses after training in one of the core jobs.
- 0300 Basic Infantry Marine – Sgt–Pvt
- *0311 Rifleman[m] – Sgt–Pvt
0312 Riverine Assault Craft (RAC) Marine[f] (FMOS "Any 03XX") – GySgt–PFC (MOS deleted before 2020)
- 0313 Light Armored Reconnaissance Marine – Sgt–Pvt
0314 Rigid Raiding Craft (RRC)/Rigid Hull Inflatable Boat (RHIB) Coxswain[f] (FMOS) – SSgt–PFC (MOS deleted before 2020)
- 0316 Combat Rubber Reconnaissance Craft (CRRC) Coxswain[f] (NMOS 0311, 0321, 0369) – SSgt–PFC
- 0317 Scout Sniper[f] (NMOS 0311, 0321, 0331, 0341, 0352, 0369) – GySgt–LCpl
- 0321 Reconnaissance Marine – MGySgt–Pvt
- 0323 Reconnaissance Marine, Parachute Qualified[f] (NMOS 0321) – MGySgt–Pvt
- 0324 Reconnaissance Marine, Combatant Diver Qualified[f] (NMOS 0321) – MGySgt–Pvt
- 0326 Reconnaissance Marine, Parachute and Combatant Diver Qualified[f] (NMOS 0321) – MGySgt–Pvt
- 0327 Reconnaissance Sniper (NMOS 0321) – MGySgt–LCpl (This MOS is not yet approved by HQMC for award to enlisted Marines, but is retained as a place holder pending formal approval. It does not appear in NAVMC 1200.1G, MOS Manual, dated 12 May 2021, nor in any other formal message traffic.)
- *0331 Machine Gunner[m] – Sgt–Pvt
- *0341 Mortarman[m] – Sgt–Pvt
*0351 Infantry Assault Marine[m] – Sgt–Pvt (MOS deleted 30 September 2020)
- *0352 Antitank Missile Gunner[m] – Sgt–Pvt
0353 Ontos Crewman[d] (MOS deleted c. 1973)
- 0363 Light Armored Reconnaissance Unit Leader – GySgt–SSgt (Added 1 October 2017)
- 0365 Infantry Squad Leader[f] (NMOS 0311, 0331, 0341, 0352) – Sgt
- 0367 Light Armored Reconnaissance Master Gunner (NMOS 0313, 0363, 0393) – MGySgt–Sgt (Added 1 October 2017)
- 0369 Infantry Unit Leader – GySgt–SSgt
- 0372 Critical Skills Operator (CSO) – MGySgt–Sgt
- 0393 Light Armored Reconnaissance Operations Chief – MGySgt–MSgt (Added 1 October 2017)
- 0399 Operations Chief – MGySgt–MSgt
- 0301 Basic Infantry Officer[a]
- 0302 Infantry Officer[a] – LtCol–2ndLt
- 0303 Light-Armored Reconnaissance (LAR) Officer (NMOS 0302)[f]
- 0306 Infantry Weapons Officer[c] – CWO5–CWO2
- 0307 Expeditionary Ground Reconnaissance (EGR) Officer (NMOS 0202, 0203, 0302)[f] – LtCol–2ndLt
- 0370 Special Operations Officer[a][n] – LtCol–Capt
57 Chemical, Biological, Radiological, and Nuclear (CBRN) Defense
Formally known as Nuclear, Biological and Chemical Defense (NBCD)
- 5700 Basic Chemical, Biological, Radiological, and Nuclear (CBRN) Defense Marine – SSgt–Pvt
- 5711 Chemical, Biological, Radiological, and Nuclear (CBRN) Defense Specialist – Sgt–Pvt
- 5713 Chemical, Biological, Radiological, and Nuclear (CBRN) Responder – Sgt–Pvt
- 5769 Chemical, Biological, Radiological, and Nuclear (CBRN) Defense Chief - MGySgt-SSgt
- 5701 Basic CBRN Defense Officer[c]
- 5702 Chemical, Biological, Radiological and Nuclear (CBRN) Defense Officer[c] - CWO5-WO