How to Get Your Merchant Mariner Credential (MMC): A Step-by-Step Walkthrough
The MMC is the single credential every US professional mariner needs. This step-by-step walkthrough covers the application, medical exam, sea-time documentation, and training in the order you'll tackle them.
What Is the MMC?
The Merchant Mariner Credential (MMC) is issued by the U.S. Coast Guard (USCG) and is the primary document that establishes your professional qualifications. It replaced the separate Merchant Mariner's Document (MMD) and Merchant Mariner License (MML) in 2014. Your MMC lists every rating, endorsement, and license you hold — from an entry-level Ordinary Seaman rating to a Master of Ocean Vessels license.
Who Needs an MMC?
Any person who works in a credentialed position aboard a USCG-inspected vessel operating on US navigable waters or on the high seas needs an MMC. This includes deckhands on towboats, officers on offshore supply vessels, engineers on passenger ships, and many other roles. Some very small vessels or certain limited positions may not require one — check with your employer or the USCG National Maritime Center (NMC) for your specific situation.
Step 1: Complete the Application (CG-719B)
The application is submitted to the NMC through its online portal or a Regional Exam Center, using form CG-719B. You'll create an account, complete the form, and upload supporting documents. There is a non-refundable evaluation fee. Make sure the name on your application matches your government-issued ID exactly to avoid delays.
Step 2: Pass the USCG Medical Exam (CG-719K)
A current USCG medical certificate (CG-719K) is required for most MMC endorsements. The exam must be conducted by a licensed physician. It covers vision, color perception, hearing, cardiovascular health, and the absence of disqualifying conditions. Certificates are generally valid for up to two years. If you have a medical condition, the NMC can advise whether a waiver or review is required.
Step 3: Gather Your Sea Service Documentation
Sea time is recorded on Sea Service forms (CG-719S), completed and signed by your employer or vessel operator. Entry-level ratings require little or no sea time, while higher ratings and licenses require substantial documented service. Retain all discharge records, employment letters, and forms — the NMC may request them to substantiate your time.
Step 4: Complete Required Training
Depending on the endorsement you're seeking, you may need USCG-accepted courses. For international service, STCW Basic Safety Training is typically required. Officer endorsements add STCW modules such as Advanced Fire Fighting, radar/ARPA, and GMDSS. Upload completion certificates with your application, and verify each course's USCG acceptance before enrolling.
Step 5: Submit, Track, and Respond
After submitting, track your application status through the NMC and watch for deficiency letters requesting additional documentation. Respond promptly and keep copies of everything you send. Processing timelines vary with complexity and NMC workload, so apply well before you need the credential in hand.
Renewals and Upgrades
MMCs are valid for five years. Submit renewals well ahead of expiration to avoid a gap that keeps you off a vessel. Upgrades — moving to a higher rating or license — require meeting the new endorsement's sea-time and training requirements and filing a fresh application, processed on a similar timeline to new credentials.
A note on requirements
Credentialing rules change and often depend on your specific vessel, route, tonnage, and history. Nothing here is legal advice. Always confirm the current requirements with the USCG National Maritime Center (NMC) and with your employer or vessel operator before making career or hiring decisions. When a rule seems to conflict with your situation, an NMC deficiency letter or a call to the NMC Customer Service Center is the fastest way to get an authoritative answer.