13 Engineer, Construction, Facilities, and Equipment
Marine Corps OccFld 13 is the field for Marines who build, breach, repair, operate heavy equipment, and support engineer-style mobility and construction tasks. It includes both the high-visibility combat-engineer side and the trade-heavy equipment and maintenance side.
The work can be combat-facing, but it can also be strongly mechanical, construction-focused, or facilities-oriented depending on the MOS.
The Marine MOS overview page says Marines in this field handle duties like welding and metalworking and are responsible for the maintenance, operation, and repair of heavy engineering equipment. That is accurate, but it still understates how broad the field really is.
Some Marines in 13 spend more time operating or maintaining equipment. Others work in breaching, construction, or field engineering. The common thread is practical support to the force through physical capability and technical skill.
At a Glance
| Area | What to know |
|---|---|
| Field purpose | Support mobility, survivability, construction, facilities, and heavy-equipment operations for Marine units |
| Representative enlisted roles | 1341 Engineer Equipment Mechanic, 1345 Engineer Equipment Operator, 1371 Combat Engineer |
| Screening themes | Mechanical comfort, field discipline, equipment familiarity, and readiness for demanding working conditions |
| Training anchor | Engineer and equipment-focused schooling after initial Marine qualification |
| Reserve note | Reserve engineer opportunities exist, but the exact specialty mix depends on the unit and local structure |
Which Role Fits You?
Choose 1341 Engineer Equipment Mechanic if you get the call at 0400.
Choose 1345 Engineer Equipment Operator if you climb into the cab at 0600.
Choose 1371 Combat Engineer if the section gets the order to breach a wire obstacle.
Choose 1391 Expeditionary Fuels Technician if a ch-53 lands at the forward arming and refueling point.
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
- 1341 Engineer Equipment Mechanic : You get the call at 0400
- 1345 Engineer Equipment Operator : You climb into the cab at 0600
- 1371 Combat Engineer : The section gets the order to breach a wire obstacle
- 1391 Expeditionary Fuels Technician : A CH-53 lands at the Forward Arming and Refueling Point
Related Resources
If you want to keep 13-field options open, start with the ASVAB guide and PiCAT guide so you are not boxed out of better technical jobs early. Then compare the field with 04 Logistics and 03 Infantry to see whether you want engineer work, support work, or direct combat-arms work.