Merchant Mariner Credential

The Merchant Mariner Credential (MMC) is a credential issued by the United States Coast Guard in accordance with guidelines of the International Convention on Standards of Training, Certification and Watchkeeping for Seafarers (STCW) to United States seafarers in order to show evidence of a mariner's qualifications.

Previous to April 15, 2009, applications for credentials still had to be made in person at an REC to provide fingerprints and proof of identity.

Now, TSA collects the fingerprints and proof of identity and forwards the information to the Coast Guard's National Maritime Center (NMC).

One organization said that the consolidation reduced the merchant marine officer license, a certificate of professional achievement and status, into a work permit.

[4] Since March 1, 2024, the MMC is presented on one sheet of 8.5"x11" waterproof and tear-resistant synthetic paper, and contains several security measures including micro-printing, foiling, and intricate patterns.

Thus new MMCs are only produced for original and renewals; raises in grade, removal or limitations, or addition of endorsements do not require a new credential.

The endorsement pages are overprinted with a transparent plastic 'watermark' with the words 'Merchant Mariner Credential' and the seal of the United States.