
Machinists Mate(MM Navy Rating)
Machinists Mates operate and maintain ship propulsion systems including steam turbines, reduction gears, and associated auxiliary equipment. Nuclear-trained MMs serve on submarines and carriers.
Overall
Quick Stats
Security Clearance
No Clearance — Open to Permanent Residents
This rate does not require a security clearance and is open to lawful permanent residents (green card holders) as well as U.S. citizens.
ASVAB Requirements
Current (temporary) line-score options — meet any one
- VE+AR+MK+AS≥180
- VE+AR+MK+AO≥185
Who This Is Best For
Best for mechanically inclined individuals who want deep understanding of how complex propulsion systems work together. Transferable skills for power plant operations, marine engineering, and industrial maintenance careers. Ideal for someone who prefers comprehensive mechanical knowledge over surface-level generalization.
+Pros
- ✓Active enlistment bonus available
- ✓Strong opportunity advancement outlook
- ✓Strong civilian career transition
–Cons
- ✗Significant sea duty
Real Opinions
+Positive
“Engineering rates get a bad rap but the job security and trade skills are legit. I went straight into a union job.”
“Overall very rewarding and well-paying for the military. A good Machinist's Mate will never be short of civilian career opportunities — HVAC technician, operating engineer, non-nuclear power plant work. I learned amazing skills working on engines and fuel systems that carried directly into civilian life.”
–Negative & Mixed
“Underway life in engineering is hot, loud, and exhausting. You will stand watch in some miserable conditions.”
“Over the course of service, the Navy can be both the best and worst experiences, with sailors learning a lot but at the cost of their sanity.”
Page 1 of 2
Share your opinion about MM
0 charsRecruiter vs Reality
What the recruiter says vs. what it's actually like.
🫡 Recruiter says
“Engineering rates are always in demand and you will learn a valuable trade!”
💀 Reality
Source: MyNavyRates researchThe trade skills are real but underway life in engineering spaces is hot, loud, and physically demanding. Watch rotations can be exhausting, especially on older ships.
🫡 Recruiter says
“MM has good advancement opportunities.”
💀 Reality
Source: navy dataMM advancement has been average to below average in recent cycles. Check the current promotion percentages before assuming fast advancement.
Page 1 of 4
Horror Stories
Real stories people have shared about this rate. Swipe to browse.
“A valve bonnet blew off a high-pressure steam line aboard USS Iwo Jima flooding the boiler room with 850-degree superheated steam. Ten of eleven sailors died. The valve had been repaired with wrong-material brass fasteners by a contractor.”
Story 1 of 6
Share a horror story about MM
0 charsRelated 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