USCG MMC

Overview

The Merchant Mariner Credential (MMC) is the credential the U.S. Coast Guard issues to mariners who work on U.S.-flag vessels. It is not one single exam. It carries one or more endorsements, such as officer, rating, radio officer or staff officer, and each endorsement has its own requirements, which may include a Coast Guard examination.

The Coast Guard's National Maritime Center site could not be read when this page was prepared. The facts below come from the federal regulations in Title 46 of the Code of Federal Regulations, Part 10, as published on eCFR. Confirm current details, forms and exam content with the National Maritime Center before applying.

Who can apply

Officer endorsements are open only to U.S. citizens, with one exception: endorsements as Operator of Uninspected Passenger Vessels on undocumented vessels. For other endorsements, such as ratings, an applicant must be a U.S. citizen, a lawful permanent resident, or a foreign national enrolled at the U.S. Merchant Marine Academy. Proof of citizenship or alien status goes to the Transportation Security Administration with the TWIC application.

Exam pattern

The regulations set out the application route rather than one fixed paper. For an original MMC the applicant must provide:

• proof of holding a valid Transportation Worker Identification Credential (TWIC) or of having applied for one;

• proof of passing the required vision, hearing, medical and physical exams, or a valid Coast Guard medical certificate;

• evidence of passing a chemical test for dangerous drugs, or of qualifying for an exemption;

• a completed, signed application, the applicable fees, and an oath to perform duties faithfully and obey lawful orders;

• sea service records, STCW course material and consent to a National Driver Register check, depending on the endorsements sought.

Where an endorsement needs an examination, it is a separate step from evaluation, and its fee is charged separately.

Marking and results

Before issuing an MMC the Coast Guard completes a criminal record review and a National Driver Register check, and verifies the TSA information, including fingerprints and proof of citizenship. It will not issue an MMC until the mariner holds a valid TWIC.

Fees

Fees come in three parts: evaluation, examination and issuance. The table shows amounts listed in 46 CFR 10.219 in the regulation as read in 2026.

STCW endorsements carry no fee. Only one issuance fee is charged for each MMC, however many endorsements it holds. Applicants may pay everything when they apply, or pay evaluation on submission, examination before testing and issuance before the credential is released. Active-duty and selected-reserve members of the uniformed services, among others, are exempt under the regulation.

How to apply

An application can be for an original MMC, a renewal, a duplicate, a raise of grade or a new endorsement. Submit the application with the required evidence and the evaluation fee. An application stays valid for 12 months from the date the Coast Guard approves it, and all requirements must be met before issuance.

After the exam

An MMC can be renewed at any time while valid and for one year after it expires. Renewal needs a valid TWIC or proof of applying for one, drug-test evidence or an exemption, a medical certificate for national endorsements, the expired credential, fees, and consent to a National Driver Register check. The applicant must also show one of several routes to current knowledge, such as at least one year of sea service in the past five years or approved training. A mariner who misses the one-year window must show continued knowledge through approved coursework or retake the original exams. A Document of Continuity can preserve a record but does not authorise working as a mariner.