🔧 Mechanical & maintenance
Diagnosing and fixing what the force runs on — vehicles, powertrains, generators, and heavy equipment.
What they do
Maintenance keeps the fleet moving. Mechanics diagnose and repair wheeled and tracked vehicles, engines, transmissions, and hydraulics; utilities and power-generation techs keep generators and environmental systems running; machinists and allied-trades specialists fabricate and repair parts.
It is hands-on diagnostic work with modern diagnostic computers as much as wrenches.
Jobs & codes by branch
Representative jobs in this field and their military occupation codes — not a complete list; each branch has many more and codes change. Use the official job finders below for the full, current list.
Army
91A M1 Abrams Tank System Maintainer · 91B Wheeled Vehicle Mechanic · 91C Utilities Equipment Repairer · 91D Power-Generation Equipment Repairer · 91E Allied Trades Specialist (machinist/welder) · 91F Small Arms/Artillery Repairer · 91G Fire Control Repairer · 91H Track Vehicle Repairer · 91J Quartermaster & Chemical Equipment Repairer · 91L Construction Equipment Repairer · 91M Bradley Fighting Vehicle System Maintainer · 91P Artillery Mechanic · 91S Stryker Systems Maintainer · 91X Maintenance Supervisor
Navy
MM Machinist’s Mate · EN Engineman · GSM Gas Turbine Systems Mechanic · GSE Gas Turbine Systems Electrical · HT Hull Maintenance Technician · MR Machinery Repairman · EM Electrician’s Mate
Air Force
2T3X1 Mission Generation Vehicular Equipment Maintenance · 2T3X7 Vehicle Management & Analysis · 2A6X1 Aerospace Propulsion · 2A6X2 Aerospace Ground Equipment · 2R1X1 Maintenance Management Production
Marine Corps
3521 Automotive Organizational Mechanic · 3522 Automotive Intermediate Mechanic · 2141 AAV Repairer/Technician · 2131 Towed Artillery Systems Technician · 2147 LAV Repairer/Technician · 1341 Engineer Equipment Mechanic
Coast Guard
MK Machinery Technician · DC Damage Controlman · EM Electrician’s Mate
ASVAB areas that matter
Mechanical Comprehension (MC) and Auto & Shop (AS) matter most, with Electronics Information (EI). Your AFQT score decides whether you can enlist; individual subtests combine into “line scores” that set which jobs you qualify for. Prepare with our free ASVAB practice tests.
How it transfers to civilian work
Direct transfer to automotive and diesel technician, heavy-equipment and fleet mechanic, machinist, and power-generation/energy roles — automotive, transportation, manufacturing, and energy industries. Credentials: ASE certifications, EPA 608, CDL, manufacturer-specific (Cat, Cummins) training.
See every job & the exact requirements
Codes, availability, and ASVAB minimums vary by branch and change often — confirm on each branch's official job finder: Army ↗ · Navy ↗ · Air Force ↗ · Marine Corps ↗ · Space Force ↗ · Coast Guard ↗.