21 Ground Ordnance Maintenance
Marine Corps OccFld 21 is the maintenance field that keeps ground weapons systems and combat vehicles working when units need them. It is one of the most technical support communities that still sits close to operational readiness.
This field fits Marines who like tools, procedures, inspection work, and the responsibility that comes with touching important equipment instead of just using it.
The field covers both weapon-system maintenance and vehicle maintenance. That means some MOSs stay close to armories and weapons accountability, while others live in vehicle shops and readiness sections that support maneuver units directly. It is a strong fit for Marines who want technical work that still has a direct effect on the operating forces.
At a Glance
| Area | What to know |
|---|---|
| Field purpose | Maintain and restore ground weapons systems, combat vehicles, and related ordnance equipment |
| Representative roles | Small-arms repair, artillery-systems maintenance, amphibious-vehicle repair, and light-armored-vehicle repair |
| Screening themes | Mechanical comfort, maintenance discipline, accountability, and patience with technical procedures |
| Training anchor | Boot Camp, Marine Combat Training, and formal ordnance-maintenance schooling before fleet specialization |
| Reserve note | Reserve relevance depends on whether a local unit actually supports the matching platforms or equipment |
Which Role Fits You?
Choose 2111 Small Arms Repairer/Technician if every marine is a rifleman.
Choose 2131 Towed Artillery Systems Technician if the gun line depends on the shop.
Choose 2141 Amphibious Combat Vehicle Repairer/Technician if the marine corps has fewer than two hundred 2141s across the entire active force at any given time.
Choose 2147 Light Armored Vehicle Repairer/Technician if the light armored vehicle sits between the humvee and the tank.
Common Entry Requirements
All enlisted Marines in this occupational field enlist with a minimum AFQT of 31, a high school diploma, U.S. citizenship, and MEPS medical clearance. Boot Camp is the first training gate: 13 weeks at MCRD San Diego or Parris Island. After graduation, Marines complete Marine Combat Training or the Infantry Training Battalion before attending their MOS-specific school. See each role’s profile below for specific ASVAB line scores, training details, and additional requirements.
Career Field Directory
- 2111 Small Arms Repairer/Technician : Every Marine is a rifleman
- 2131 Towed Artillery Systems Technician : The gun line depends on the shop
- 2141 Amphibious Combat Vehicle Repairer/Technician : The Marine Corps has fewer than two hundred 2141s across the entire active force at any given time
- 2147 Light Armored Vehicle Repairer/Technician : The Light Armored Vehicle sits between the Humvee and the tank
Related Resources
Use the ASVAB guide and PiCAT guide for broad score planning. Then compare 18 Tank/AAV/ACV if you want the crew side of the same vehicle community instead of the maintenance side.