CFR > Title 46 - Shipping > CHAPTER I—COAST GUARD, DEPARTMENT OF HOMELAND SECURITY > SUBCHAPTER B—MERCHANT MARINE OFFICERS AND SEAMEN (parts 10 to 16) > PART 10—MERCHANT MARINER CREDENTIAL > SUBPART B—General Requirements for All Merchant Mariner Credentials (§10.201 to §10.239) > 10.205—Validity of a merchant mariner credential.

10.205—Validity of a merchant mariner credential.

(a) An MMC is valid for a term of five years from the date of issuance.
(b) All endorsements are valid until the expiration date of the MMC on which they appear.
(c) A mariner may not serve under the authority of an MMC past its expiration date. An expired MMC may be renewed during an administrative grace period of up to one year beyond its expiration date as per § 10.227(f) of this part.
(d) When an MMC is renewed or re-issued before its expiration date in accordance with § 10.227, the MMC that has been replaced becomes invalid.
(e) An MMC is not valid until signed by the applicant and a duly authorized Coast Guard official.
(f) A mariner's STCW endorsement is valid only when the related officer or rating endorsement is valid.
(g) A mariner's endorsements authorize the holder to serve in any capacity endorsed on the MMC, or in any lower capacity in the same department, or in any capacity covered by a general endorsement thereon.
(h) If a mariner chooses to renew his or her license, MMD, COR, or STCW endorsement and receive their first MMC, the Coast Guard may also renew all other credentials for which the mariner is qualified.