(a) An MMC is valid for a term of 5 years from the date of issuance. Except upon the written request for the immediate issuance by the applicant, the Coast Guard will post-date the issuance of an MMC renewal that includes no other transactions up to 8 months from the date that the Coast Guard accepts a complete application as required in this part. If the expiration date of the mariner's active credential is beyond 8 months of the date that the Coast Guard accepts a complete application as required in this part, the new credential issue date will be 8 months from the date of application acceptance at which time the currently active credential will become invalid in accordance with paragraph (d) of this section. Otherwise, the new credential issue validity date will coincide with the expiration date of the active credential held by the mariner. All other MMC transactions will be processed for immediate issuance.

(b) All endorsements, unless otherwise noted, 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 1 year beyond its expiration date as per § 10.227(h) of this part.

(d) When an MMC is renewed or re-issued before its expiration date in accordance with § 10.227, of this part the MMC that has been replaced becomes invalid unless otherwise noted in paragraph (a) of this section.

(e) An MMC is not valid until signed by the applicant and a duly authorized Coast Guard official.

(f) 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.

(g) 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.

(h) When a Document of Continuity is replaced with an MMC re-issued in accordance with § 10.227 of this part, the Document of Continuity that has been replaced becomes invalid. In the event that not all endorsements on a Document of Continuity are activated, a new Document of Continuity will be issued for the remaining endorsements.