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Navy Rating · Engineering

MMA Machinist's Mate, Non-Nuclear, Submarine Auxiliary

Current service use not established

This code is listed in the directory. Inclusion alone does not confirm current service use.

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Overview

Nonnuclear submarine auxiliary machinist's mates operate, maintain, and repair damage control equipment, diesel engines, diesel support systems, hydraulic systems, and atmosphere control equipment. They also service oxygen generation, refrigeration, compressed air and gas, potable water, seawater, sanitary, and plumbing systems at organizational and intermediate levels.

Minimum ASVAB: VE+AR+MK+EI 207 or AR+GS+MC+EI 207

ASVAB policy: Not policy-reviewed · coverage unknown · as of 2026-10-19

Program scope has not been reviewed.

Policy applicability and coverage of the program's score routes have not been reviewed. Shown-route arithmetic is not an eligibility decision.

Source: milpersman-1306-618-rating-list-2026-04 (source date 2026-04). Policy applicability has not been established.

See if you would hit this score: free ASVAB practice test

Core Skills

  • Atmosphere control and oxygen-generation equipment maintenance
  • Hydraulic and compressed-gas systems repair
  • Diesel engine and support-system repair
  • Potable water and sanitary systems maintenance

Civilian Career Paths

Career associations are editorial assessments of the cited evidence, not an official crosswalk unless the evidence explicitly says so. O*NET supplies civilian occupation information, not proof of a military match. Related experience does not confer civilian qualifications. Tasks and tools below describe civilian work, not military training.

Maintenance and Repair Workers, General

Maintaining and repairing submarine hydraulic, refrigeration, compressed-air, and plumbing systems transfers directly to multisystem equipment maintenance.

How to prepare: Build a repair portfolio describing the equipment serviced, faults addressed, and repairs completed, emphasizing systems used by the target employer.

What the civilian work involves
  • Perform routine maintenance, such as inspecting drives, motors, or belts, checking fluid levels, replacing filters, or doing other preventive maintenance actions.
  • Inspect, operate, or test machinery or equipment to diagnose machine malfunctions.
  • Repair machines, equipment, or structures, using tools such as hammers, hoists, saws, drills, wrenches, or equipment such as precision measuring instruments or electrical or electronic testing devices.

Bus and Truck Mechanics and Diesel Engine Specialists

Operating, maintaining, and repairing submarine diesel engines and their support systems provides a foundation for civilian diesel-engine service.

How to prepare: Take hands-on training in vehicle diesel diagnostics, including electronic engine controls, before targeting truck or bus repair positions.

What the civilian work involves
  • Use handtools, such as screwdrivers, pliers, wrenches, pressure gauges, or precision instruments, as well as power tools, such as pneumatic wrenches, lathes, welding equipment, or jacks and hoists.
  • Attach test instruments to equipment, and read dials and gauges to diagnose malfunctions.
Civilian tools and software (examples)
  • Computerized maintenance management system software CMMS
  • Cummins INSITE

Stationary Engineers and Boiler Operators

Experience operating and maintaining diesel engines, compressed-air systems, refrigeration equipment, and water systems overlaps with stationary-plant auxiliary equipment work.

How to prepare: Seek supervised plant-operations training that covers boiler controls and steam systems beyond the verified MMA duties. Some state and local licenses require experience and a written exam, with license classes limiting the equipment type and size permitted for unsupervised operation.

What the civilian work involves
  • Operate or tend stationary engines, boilers, and auxiliary equipment, such as pumps, compressors, or air-conditioning equipment, to supply and maintain steam or heat for buildings, marine vessels, or pneumatic tools.
  • Analyze problems and take appropriate action to ensure continuous and reliable operation of equipment and systems.
Civilian tools and software (examples)
  • Building management system software

Training & Development

Choose credentials for your target role. COOL funding markers describe program listings, not a guarantee of eligibility or funding.

Career Growth

  • Certified Maintenance and Reliability Professionals (CMRP)

    Support progression from equipment repair toward broader maintenance and reliability responsibilities.

    Eligibility and preparation: No education or work-experience minimum; candidates must not have taken the examination within the preceding six months.

    For: Maintenance and Repair Workers, General, Stationary Engineers and Boiler Operators

Notes & Sources

Evidence for this guidance (7 documents)
  1. NAVPERS 18068F Vol I (NEOCS, Jan 2026 edition): AUXILIARY (MMA)

    [1] Rating chapter "SCOPE OF RATING"; cached text line 51888; NAVPERS 18068F Vol I, 2026-01 edition

    Supports: Atmosphere control and oxygen-generation equipment maintenance, Hydraulic and compressed-gas systems repair, Diesel engine and support-system repair, Potable water and sanitary systems maintenance, Maintenance and Repair Workers, General (O*NET 49-9071.00), Bus and Truck Mechanics and Diesel Engine Specialists (O*NET 49-3031.00), Stationary Engineers and Boiler Operators (O*NET 51-8021.00)

  2. O*NET: Maintenance and Repair Workers, General

    [2] O*NET 30.3 occupational data

    Supports: Maintenance and Repair Workers, General (O*NET 49-9071.00)

  3. O*NET: Bus and Truck Mechanics and Diesel Engine Specialists

    [3] O*NET 30.3 occupational data

    Supports: Bus and Truck Mechanics and Diesel Engine Specialists (O*NET 49-3031.00)

  4. O*NET: Stationary Engineers and Boiler Operators

    [4] O*NET 30.3 occupational data

    Supports: Stationary Engineers and Boiler Operators (O*NET 51-8021.00)

  5. Bureau of Labor Statistics: Stationary Engineers and Boiler Operators

    [5] How to Become a Stationary Engineer or Boiler Operator; Licenses, Certifications, and Registrations; page dated 2026-08-27, retrieved 2026-09-23

    Supports: Stationary Engineers and Boiler Operators (O*NET 51-8021.00)

  6. COOL credential mapping: Certified Maintenance and Reliability Professionals (CMRP)

    [6] MMA cached COOL credential feed

    Supports: Certified Maintenance and Reliability Professionals (CMRP)

  7. Society for Maintenance and Reliability Professionals: CMRP eligibility

    [7] Eligibility; retrieved 23 September 2026

    Supports: Certified Maintenance and Reliability Professionals (CMRP)

Defense contractor jobs for MMA

Descriptions may be summarized for clarity. Verify all information with your branch career counselor or official military documentation before making career decisions.

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