MMA

Machinist's Mate Auxiliary(MMA Navy Rating)

Machinist''s Mate Auxiliary (MMA) is the submarine non-nuclear mechanical specialty. MMAs own everything aft of the reactor compartment that isn''t primary propulsion: high-pressure air, hydraulics, atmosphere control (CO2 scrubbers, O2 generators, H2 burners), the trim and drain systems, ship''s service turbine generators'' auxiliaries, weapons-handling hydraulics, the outboard plant, and the atmosphere-analysis equipment that keeps the crew alive on long submerged runs.

MMA is a non-nuclear submarine rating distinct from MMN (Machinist''s Mate Nuclear), which runs the primary plant. MMA sailors are the boat''s mechanical generalists — they diagnose and repair across dozens of auxiliary systems and stand watch as Auxiliaryman of the Watch (A-Gang), Chief of the Watch, and Diving Officer of the Watch.

The pipeline runs from Basic Enlisted Submarine School in Groton into MMA ''A'' School, also at Naval Submarine Base New London. Work is physically demanding, hot, and tight-quartered. Civilian translation is strongest toward industrial mechanic, HVAC-R, and maritime engineering trades.

Overall

4.8/10

Burnout5.1

Lifestyle3.0

Quick Stats

Enlistment BonusNo active bonus

Civilian Sector Transferability$65k–$110k

Advancement OutlookAverage

Manning %92%

Initial Contract3 yr active /

Medical Requirements

✓Vision: Corrects to 20/20
✓Normal color perception
✓Normal hearing
✓No speech impediment

Security Clearance

Secret~$3K–$15K civilian sector value

Requires a National Agency Check with Local Agency Check and Credit Check (NACLC). Processing typically takes 1–3 months and is initiated early in your training pipeline.

ASVAB Requirements

AFQT Minimum

Who This Is Best For

Best for hands-on mechanical candidates who want submarine duty without the nuclear pipeline, and who are looking toward industrial-mechanic, HVAC-R, or maritime trade careers afterward.

+Pros

✓Strong civilian career transition

–Cons

✗Significant sea duty

Real Opinions

+Positive

✓

“I kept the air clean. If you want to live under the water in a steel tube that's closed on both ends for months at a time, you need people like me.”

The Lean Submariner|

✓

“Proudest work of my life with some of the best men I have ever known.”

The Lean Submariner|

–Negative & Mixed

No negative reviews yet.

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Recruiter vs Reality

What the recruiter says vs. what it's actually like.

🫡 Recruiter says

“A-Gang keeps the sub habitable — you'll be the hero of the boat.”

💀 Reality

Source: https://theleansubmariner.com/2019/06/07/it-wasnt-for-the-glory-life-as-a-submarine-auxiliaryman/

MMAs run oxygen generators, CO2 scrubbers, hydraulics, HP air, diesel, and sanitary systems. Retired A-Ganger: "We were in charge of the shit tanks too. If you really want to see grown men cry, shut down those babies for a few hours."

🫡 Recruiter says

“Great for a mechanical civilian career — HVAC, refrigeration, diesel.”

💀 Reality

Source: https://www.cool.osd.mil/usn/moc/index.html?moc=mma

The Navy-to-civilian translation is real, but MMA systems are sub-specific (EAB, CAMS, O2 gens). Generic HVAC/refrigeration employers may not recognize Navy training without extra certs. Civilian diesel/marine-mechanic certs are the most direct path.

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Related Reading

Guides on picking a rate, ASVAB, bonuses, promotion, and life after the Navy.

Getting Started

How do you choose the right Navy rate for you?

Choosing a Navy rate means weighing your ASVAB scores, lifestyle preferences, civilian career goals, and willingness to deploy or go to sea. Start by identifying which ratings you qualify for, then narrow the list by what matters most to you.

Getting Started

What is the ASVAB and what scores do you need?

The ASVAB is a multi-aptitude test that determines which Navy ratings you qualify for. Your sub-test scores combine into line scores, and each rating has minimum line-score requirements. Higher scores open more options.

Career & Pay

Which Navy rates have the biggest enlistment bonuses in 2026?

Active Component (Active Duty) only. Per the CNRC GENADMIN dated 10 April 2026, the Nuclear Field carries the biggest source-rate bonus at $40,000 (FY26 ship dates) and a $75,000 EB cap. Top Special Operations and submarine ratings sit at $30,000 EBSR with a $60,000 EB cap. All other rates cap at $50,000. The Loan Repayment Program adds up to $65,000 on top, separately. Reserve component (SELRES) bonuses are governed by a different message and are not covered here.

Career & Pay

How does promotion work in the Navy?

Advancement Outlook

E-2 to E-4 Advancement Outlook

Time to E-4: 30 months total

E-1 → E-2: 9 months at E-1. Automatic
E-2 → E-3: 9 months at E-2. Automatic
E-3 → E-4: 12 months at E-3. Automatic

E-4 is automatic — competitive advancement starts at E-5

How to advance faster to E-4

Your recruiter can process you in at E-2 or E-3 on day one if you qualify. Every rung skipped shortens the path to E-4 by months. Official transcripts / certificates required at enlistment.

E-2 →Easy
2 years of JROTC completed. Easiest common path if your high school offers JROTC.
E-2 →Moderate
24+ semester hours/ 36+ quarter hours of college credit (below the associate's threshold). Roughly one full year of college.
E-2 →Moderate
Civil Air Patrol Billy Mitchell Award. Achievable with consistent cadet participation, but requires testing and leadership time.
E-2 →Moderate
Sea Cadet Corps — reaching the Sea Cadet E-2 rate (join by age 17).
E-2 to E-3 →Moderate
Boot camp leadership roles — roles don't auto-pin rank. Advancement comes from earning Honor Recruit or Hall of Fame at graduation (one award only, not stacked).
- Honor Recruit up to E-2 — effectively the #1 ranked recruit in your division (~60-80 recruits), one Sailor per division per cycle. Selection is based on cumulative performance across all three academic exams, Physical Readiness Test (PRT) scores, uniform and personnel inspections, military bearing, and peer/Recruit Division Commander (RDC) evaluations. Roles that typically compete at this level:
  - Assistant LPO (ALPO) — deputy to the LPO.
  - Master-at-Arms (MAA) — barracks cleanliness, standards, and discipline.
  - Yeoman (YN) — division admin, paperwork, and tracking.
  - Educational Petty Officer (EPO) — study groups, test prep, and academic remediation.
  - Religious Petty Officer (RPO) — coordinates chapel and religious services.
  - Athletic Petty Officer (APO) — leads PT and fitness assessments.
  - Mail Petty Officer — handles mail distribution and tracking.
  - Section Leaders — squad-level leaders below the division-wide roles.
- Hall of Fame up to E-3 — the most elite recognition at Recruit Training Command (RTC), awarded Navy-wide rather than per division. Requires exceptional performance in every training metric: top-tier scores on all three academic exams (typically 90%+), "Outstanding" on the final Physical Readiness Test (PRT), near-perfect uniform and personnel inspections, held a division leadership role with strong performance, and zero remediation, infractions, or negative marks across the full training cycle. Senior leadership roles positioned to compete:
E-3 →Moderate
3 years of JROTC completed (any service branch). Straightforward if your high school has the program — three school years of enrollment.
E-3 →Hard
Eagle Scout (BSA) or Gold Award (GSUSA) — the highest youth scouting awards. Typically takes years of participation and a capstone service project.
E-3 →Hard
Associate's degree (or 48+ semester hours / 72+ quarter hours of college credit, 100-level or higher from an accredited institution). Two years of full-time college.
E-3 →Hard
Civil Air Patrol Earhart Award. Uncommon — only a small fraction of CAP cadets reach this level.
E-3 →Hard
Sea Cadet Corps — reaching the Sea Cadet E-3 rate (join by age 16).

Ceiling is E-3 at accession — stacking qualifications doesn't push you to E-4 out of the gate.

Ways to accelerate E-4 after you're in

Very HardMeritorious Advancement Program (MAP) — Command-nominated promotion that skips the exam entirely. Each command gets a small seasonal quota of MAP slots and hands them to the top performers based on evaluation ranking. Fastest path on paper, but you're competing directly with every other sailor at your command.

Rules can change — verify current criteria with your recruiter and in the latest Navy Recruiting Manual (COMNAVCRUITCOM) before signing any paperwork that assumes a specific entry paygrade.

E-5 and E-6 Advancement Outlook

Average★☆★☆

1 of 4 factors working in your favor · 1 working against you

▼
Manning
E5 85%E6 100%
E5 is balanced while E6 is overmanned. Your advancement outlook depends on which paygrade you're promoting into next.
Source: N12 Enlisted Community Status Brief, 1 Apr 26
●
Enlistment bonus
No
No active enlistment bonus for this rate. Most ratings do not offer one in any given fiscal year, so this is a neutral signal on its own.
▲
Overall Selective Reenlistment Bonus (SRB) Outlook
Competitive SRB added/increased · SRB reduced/eliminated
Navy is paying a substantial bonus to retain sailors. Strong signal that billets are staying empty at senior paygrades.

Bonuses — Click here to see your military pay

All Active CNRC Enlistment Incentives

Active Duty

Source: CNRC GENADMIN 10 APR 26 — effective Apr 12, 2026, contracts authorized through Dec 31, 2026 (NDAA 2026)

Active Component only. Reservist (SELRES) shipping bonuses are set by a separate CNRF incentive message — ask your recruiter.

Bonuses can stack up to the rating's EB cap; LRP is independent. Footnote numbers match the source GENADMIN.

Shipping Bonus (EBSHP)

Earned at RTC graduation. Cannot be recouped post-RTC. AFQT ≥ 31 required.

ALL-—

April FY26 – July FY26

$5,000[1, 2, 3, 4, 5, 8, 9]

EBSHP Notes

1EBSHP eligibility exists only while the FS is in DEP — they may not reclassify at RTC. Earned and payable upon RTC graduation. Cannot be recouped due to post-RTC reclassification or separation.
2NRC classifiers must list EBSHP separately on the NAVCRUIT 1133/52 Enlistment Guarantee.
3EBSHP is intended to fill shipping gaps during the authorized window. Recruiters should not advise FSs to roll out and back in to chase a bonus.
4Future Sailors must have an AFQT score of 31 or higher to be eligible for EBSHP.
5If the Navy itself moves a Sailor's ship date to align with an A-school class convening date, the EBSHP entitlements are preserved on the Annex and SOU.
8FSs scheduled to ship after the designated period who roll into an authorized month, OR who sign a new contract / reclassify into the rating to ship in the designated month(s), are eligible.
9This universal EBSHP applies to all Future Sailors scheduled to ship during the designated period and may be combined with any rating-based EBSHP for which the FS qualifies.

Cross-cutting Policy Notes

1Future Sailors with Tier 3 education credentials (e.g., HiSET / GED / alternative credential) are NOT authorized any EB.
2Prior-service members re-enlisting onto Active Duty must enter at pay grade E-4 or below, must not have received a bonus on their first enlistment, and (Navy prior-service) must have been separated from active duty for at least 12 months before shipping.
3EBHS (EB for High School) is currently NOT AUTHORIZED in this message — distinct from prior cycles when EBHS was offered.
4During lapsed appropriations, classifiers may still include EB on a contract if the DD 1966 carries the funding-availability disclaimer; payment is then subject to a future appropriation.
5Bonuses are paid in installments. Only the unearned portion of EBSR is eligible for recoupment; EBSHP/EBPST cannot be recouped after RTC graduation.

Always verify with a recruiter before signing — eligibility depends on AFQT, education tier, security-clearance adjudication, ship date, and program availability. Funding subject to congressional reauthorization of 37 USC § 331.

How to qualify & get paid

Sign a contract for this rate at MEPS with the bonus(es) listed on your NAVCRUIT 1133/52 Enlistment Guarantee — eligibility is locked at signing.
Ship to Recruit Training Command (RTC) Great Lakes inside the authorized window — EBSHP and EBPST are earned and paid at RTC graduation and cannot be recouped after.
Complete A-school (and any required follow-on C-school or qualifying course) for your rating — EBSR is earned and paid at school graduation, except for the Special-Operations pipelines, which pay later (AIRR after FRS + first duty station; SO after SQT; SB after SWCC Charlie phase; EOD/ND after their respective A-schools).
LRP is paid annually upon submission of a DD 2475; ~25% is withheld for federal taxes, and a W-2 is issued. LRP must be on your contract at accession — it cannot be added later via reclassification.

Important details & disqualifiers

All bonuses on this page are Active Component (Active Duty) only. Reservists (SELRES) follow a separate CNRF incentive message — ask your recruiter.
Future Sailors with Tier 3 education credentials (HiSET / GED / alternative) are NOT authorized any EB.
AFQT score must be ≥ 31 for EBSHP and ≥ 50 for LRP.
EBSR is the only EB type that can be partially recouped if you separate before completing the obligated service. EBSHP / EBPST cannot be recouped after RTC.
Bonus payments are subject to federal income tax withholding.
EB-for-High-School (EBHS) is currently NOT authorized in the April 2026 GENADMIN — distinct from earlier cycles when it was offered.
Funding: NDAA 2026 authorizes contracts through 31 December 2026; appropriations cover obligations through 30 September 2026; max-EB authority extends through 4 June 2028 — all subject to congressional reauthorization of 37 USC § 331.
This rate requires a security clearance — failure to obtain clearance may affect bonus eligibility (and several special-operations footnotes explicitly require an earned NEC + clearance before payment).

You May Qualify for a Navy Enlisted Classification (NEC)

Specialties within this rate you can select, some with additional compensation. Each NEC has its own training, bonus potential, and career path.

0000Any NEC or no NEC (all qualifying Sailors in this rating)

Selective Reenlistment Bonus (SRB)

🟡

First Reenlistment (17 mo to 6 yrs Active Duty)

$45,000

Max

Reduced · effective 2025-12-18

🟢

Second Reenlistment (6 to 10 yrs Active Duty)

$60,000

Max

Active (unchanged)

🟢

Third Reenlistment (10 to 14 yrs Active Duty)

$30,000

Max

Active (unchanged)

Q10BMachinist's Mate Auxiliary (MMA) Leading Chief Petty Officer (LCPO)

Machinist's Mate Auxiliary(MMA Navy Rating)

Quick Stats

Security Clearance

ASVAB Requirements

Who This Is Best For

+Pros

–Cons

Real Opinions

+Positive

–Negative & Mixed

Share your opinion about MMA

Recruiter vs Reality

Horror Stories

Share a horror story about MMA

Related Reading

How do you choose the right Navy rate for you?

What is the ASVAB and what scores do you need?

Which Navy rates have the biggest enlistment bonuses in 2026?

How does promotion work in the Navy?

Medical Requirements — detail

Remarks

Training Pipeline — Total ~32 weeks (7 months)

Calculate Your End Training Date and Holidays and Events You Will Miss During Training

Career Progression Milestones

Advancement Outlook

Bonuses — Click here to see your military pay

You May Qualify for a Navy Enlisted Classification (NEC)

Potential Civilian Post-Navy Outcomes

Post-Navy Salary Trajectory

Free Certifications & Credentials

Retention & Burnout

Lifestyle3/10

Watch Standing

Which Navy jobs set you up best for a civilian career?

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