Maintenance
Career Management Fields 91 and 94 keep the Army’s equipment in the fight. Every tank, rocket launcher, encrypted radio, and precision radar the Army fields requires trained maintainers who can diagnose faults, replace components, and verify systems are ready to operate. Without this career field, armored formations stay in the motor pool and missile batteries sit silent.
CMF 91 covers mechanical maintenance: wheeled vehicles, tracked vehicles, weapons systems, generators, utilities equipment, and construction machinery. CMF 94 covers electronics and missile system maintenance: radar, COMSEC radios, rocket systems, precision test equipment, and automated test platforms. Together, these two fields span 21 MOSs from basic mechanical work to some of the most technically demanding jobs in the enlisted Army.
The range of roles is wide. At one end, the 91B Wheeled Vehicle Mechanic works with diesel engines, hydraulic systems, and drivetrain components on trucks and tactical vehicles. At the other, the 94H TMDE Support Specialist calibrates precision measurement instruments against NIST-traceable standards using a 33-week training pipeline that rivals a two-year technical degree. Most people with a mechanical or electronics aptitude can find a slot in this field that fits their interest.
At a Glance
Mechanical Maintenance (CMF 91)
| MOS | Title | ASVAB Area | Training Length | Clearance | Civilian Equivalent |
|---|---|---|---|---|---|
| 91A | M1 Abrams Tank System Maintainer | MM 99 | 24 weeks | None | Defense contractor technician |
| 91B | Wheeled Vehicle Mechanic | MM 92 | 13 weeks | None | Diesel mechanic |
| 91C | Utilities Equipment Repairer | GM 98 | 13 weeks | None | HVAC technician |
| 91D | Tactical Power Generation Specialist | GM 98 | ~11 weeks | None | Power generator technician |
| 91E | Allied Trade Specialist | GM 98 | 13 weeks | None | Machinist/welder |
| 91F | Small Arms and Artillery Repairer | GM 93 | 7 weeks | None | Gunsmith |
| 91H | Track Vehicle Repairer | MM 87+GT 85 | ~13 weeks | None | Heavy equipment mechanic |
| 91J | Quartermaster/Chemical Equipment Repairer | MM 92 | 6 weeks | None | Industrial equipment repairer |
| 91L | Construction Equipment Repairer | MM 92 | 8 weeks | None | Heavy equipment mechanic |
| 91M | Bradley Fighting Vehicle Systems Maintainer | MM 99 | ~13 weeks | None | Armored vehicle technician |
| 91P | Self-Propelled Artillery Systems Maintainer | MM 99 | 15 weeks | None | Defense contractor technician |
| 91S | Stryker Systems Maintainer | MM 92 | 17 weeks | None | Fleet maintenance technician |
Electronic and Missile Maintenance (CMF 94)
| MOS | Title | ASVAB Area | Training Length | Clearance | Civilian Equivalent |
|---|---|---|---|---|---|
| 94A | Land Combat Electronic Missile System Repairer | EL 102 | 18 weeks | Secret | Defense electronics technician |
| 94E | Radio and Communications Security Repairer | EL 102 | 24 weeks | Secret | RF/COMSEC technician |
| 94F | Computer/Detection Systems Repairer | EL 102 | 20 weeks | Secret | Systems electronics technician |
| 94H | TMDE Support Specialist | EL 107 | 33 weeks | None | Metrology technician |
| 94M | Radar Repairer | EL 102 | ~11 weeks | Secret | Radar systems technician |
| 94P | Multiple Launch Rocket System Repairer | EL 93 | ~19 weeks | Secret | Defense systems technician |
| 94R | Avionic and Survivability Equipment Repairer | EL 98 | ~29 weeks | Secret | Avionics technician |
| 94S | Patriot System Repairer | EL 107 | ~13 weeks | Secret | Missile systems technician |
| 94Y | Automatic Test Systems Operator and Maintainer | EL 107 | ~30 weeks | Secret | ATE systems technician |
Which Role Fits You?
The best way to choose within this career field is to answer two questions: Do you prefer working with mechanical systems or electronic systems? And do you want a platform specialization or a broader role?
If you want to work on vehicles, the ground vehicle MOSs vary by platform type. Choose 91B Wheeled Vehicle Mechanic if you want the most common role in the Army, working on HMMWVs, HEMTTs, and tactical trucks at virtually every installation worldwide. Choose 91S Stryker Systems Maintainer if you want a wheeled combat vehicle with significantly more electronic complexity than a truck. For tracked armor, 91H Track Vehicle Repairer handles the broadest tracked platform portfolio, while 91A M1 Abrams and 91M Bradley are platform specialists who go deeper on a single iconic system. 91P Self-Propelled Artillery is for the Paladin specifically, and combines track vehicle mechanics with fire control electronics.
If you want to work with weapons, utilities, or construction equipment, the general mechanical MOSs offer variety. 91F Small Arms and Artillery is the go-to for people drawn to weapons systems. It’s also the shortest AIT in CMF 91 at seven weeks. 91E Allied Trade Specialist is a manufacturing and fabrication role unlike any other in the Army; you’ll machine and weld replacement parts rather than swap pre-made components. 91C Utilities Equipment Repairer and 91D Tactical Power Generation Specialist are strong options if you have an interest in HVAC, electrical systems, or diesel power, and both produce EPA certifications with direct civilian market value. 91L Construction Equipment Repairer and 91J Quartermaster and Chemical Equipment Repairer are solid choices if you want to work at engineer units or sustainment brigades with lower operational tempo.
If electronics are your strength, CMF 94 is built for you. The entry threshold is the EL (Electronics) composite, and the minimum ranges from 93 for 94P MLRS Repairer to 107 for 94H TMDE, 94S Patriot, and 94Y Automatic Test Systems. Most CMF 94 MOSs require a Secret clearance and offer training pipelines of 18 to 30 weeks. 94E Radio and Communications Security Repairer is the right pick if you want to work with tactical radios and COMSEC devices at the unit level. 94M Radar Repairer and 94S Patriot System Repairer appeal to soldiers who want to work on air defense and counterbattery systems with clear defense contractor demand after service. 94R Avionic and Survivability Equipment Repairer is one of the more selective paths: 29 weeks of AIT on aircraft electronics, producing avionics credentials that transfer into commercial aviation maintenance. 94H TMDE Support Specialist stands apart from the rest: no clearance required, the highest EL threshold in the series, and a specialization in precision calibration that few civilians understand and fewer can do.
Every role in this field shares the same basic reward structure: you fix something, it works, and someone else can do their job because of it.
Common Entry Requirements
All CMF 91 and 94 roles require a high school diploma or GED equivalent, U.S. citizenship or permanent residency, and a minimum AFQT score of 31 (high school diploma) or 50 (GED) to enlist. Most roles train at either Fort Gregg-Adams in Virginia, Fort Leonard Wood in Missouri, or Redstone Arsenal in Alabama, depending on the specialty. CMF 94 roles also require an EL (Electronics) composite score and, in most cases, eligibility for a Secret security clearance, which means no significant criminal history, minimal foreign contacts, and manageable financial history. Physical demand categories vary by role from Moderate to Very Heavy. See each role’s individual profile below for specific ASVAB composites, OPAT categories, and additional requirements.
Career Field Directory
Preparing for the ASVAB? The ASVAB study guide covers every composite used in this career field, including the MM and EL composites that most CMF 91 and 94 roles require. First-time test takers may also be eligible for the PiCAT, the at-home version of the ASVAB.
Mechanical Maintenance (CMF 91)
- 91A M1 Abrams Tank System Maintainer: 24-week AIT on the Army’s main battle tank; highest MM threshold in the tracked vehicle group
- 91B Wheeled Vehicle Mechanic: most widely assigned CMF 91 MOS; works on HMMWVs, HEMTTs, MRAPs, and tactical trucks Army-wide
- 91C Utilities Equipment Repairer: HVAC, refrigeration, and environmental control; earns EPA 608 Universal certification during AIT
- 91D Tactical Power Generation Specialist: maintains tactical generators and electrical distribution systems that power every forward operating base
- 91E Allied Trade Specialist: machines and welds replacement metal parts from raw stock; skills equivalent to a two-year machining or welding program
- 91F Small Arms and Artillery Repairer: repairs rifles, machine guns, mortars, and artillery weapons systems; shortest AIT in CMF 91 at seven weeks
- 91H Track Vehicle Repairer: broadest tracked vehicle portfolio in the series; covers Bradleys, M113s, recovery vehicles, and other platforms
- 91J Quartermaster and Chemical Equipment Repairer: maintains water purification units, field laundry systems, and decontamination equipment at sustainment units
- 91L Construction Equipment Repairer: maintains bulldozers, graders, scrapers, and excavators that support engineer construction and route clearance missions
- 91M Bradley Fighting Vehicle Systems Maintainer: platform specialist on the Bradley IFV hull, turret, and integrated weapons systems
- 91P Self-Propelled Artillery Systems Maintainer: Paladin M109A7 specialist combining track vehicle mechanics with high-voltage fire control electronics
- 91S Stryker Systems Maintainer: wheeled combat vehicle with ten variants; earns EPA 609 certification and college credits at AIT
Electronic and Missile Maintenance (CMF 94)
- 94A Land Combat Electronic Missile System Repairer: TOW, Javelin, and Bradley weapons electronics; Secret clearance required, strong defense contractor demand
- 94E Radio and Communications Security Repairer: fixes tactical radios, SATCOM terminals, and COMSEC encryption devices; one of the longer pipelines in CMF 94 at 24 weeks
- 94F Computer/Detection Systems Repairer: maintains fire control computers, battlefield surveillance systems, and detection electronics at the unit level
- 94H TMDE Support Specialist: calibrates all Army test and measurement equipment to NIST standards; highest EL threshold in the field, no clearance required
- 94M Radar Repairer: maintains SENTINEL and FIREFINDER ground-based radar systems for air defense and counterbattery fire support
- 94P Multiple Launch Rocket System Repairer: maintains M270 MLRS and M142 HIMARS rocket artillery; lowest EL threshold in CMF 94
- 94R Avionic and Survivability Equipment Repairer: repairs Army aircraft navigation, radar, and survivability systems; 29-week AIT with strong commercial avionics pathways
- 94S Patriot System Repairer: maintains Patriot missile launching stations and fire control; direct pipeline to Raytheon and defense contractor roles
- 94Y Automatic Test Systems Operator and Maintainer: operates automated test platforms used at Army depots to verify weapons system electronics
Related Resources
Explore all Army enlisted careers to compare this field against other CMF families. If your ASVAB Electronics composite is your strongest score, use our ASVAB study guide to raise it before test day. Every point above the minimum expands the number of roles you can pursue in this field.