46 CFR 10.223: Modifying or removing MMC limitations or scope

Last reviewed: October 14, 2026

This section covers changing or removing limitations on a mariner's MMC, or increasing its scope. The Coast Guard may do so when documentary evidence shows the applicant is entitled to it. A complete application must include the items listed in paragraph (c).

Applies toApplicants who hold an MMC and want its limitations changed or removed, or its scope increased.

What it says

  1. The Coast Guard may change or remove limitations it previously placed on an MMC if documentary evidence satisfies it that the applicant is entitled by experience, training, and knowledge.

    46 CFR 10.223(a)“any limitations that were previously placed upon the MMC by the Coast Guard may be changed or removed”

  2. An increase in scope may include a change in horsepower or tonnage limitations, or geographic route restrictions.

    46 CFR 10.223(a)“Such an increase in scope may include a change in horsepower or tonnage limitations, or geographic route restrictions.”

  3. Modifying or removing limitations or scope does not change the MMC expiration date, unless the applicant renews all endorsements that would appear on the MMC under § 10.227 of this part.

    46 CFR 10.223(b)“will not change the expiration date of the mariner's MMC unless the applicant renews all endorsements that would appear on the MMC under § 10.227 of this part”

  4. A complete application must include a completed signed application and proof that the mariner holds a valid TWIC or has applied for a TWIC.

    46 CFR 10.223(c)(2)“Proof that the mariner either holds a valid TWIC or has applied for a TWIC.”

  5. A complete application must include the appropriate fee as set forth in § 10.219 of this part.

    46 CFR 10.223(c)(4)“The appropriate fee as set forth in § 10.219 of this part; and”

  6. If the applicant's MMC is still valid at the time of application, the applicant must surrender the old, original credential to the Coast Guard within 30 days of issuance of the new credential.

    46 CFR 10.223(c)(5)“If still valid at the time of application, the applicant must surrender the old, original credential to the Coast Guard within 30 days of issuance of the new credential.”

  7. No limitation on any endorsement may be changed until the applicant has made up any experience deficiency and passed any necessary examination.

    46 CFR 10.223(d)“No limitation on any endorsement may be changed before the applicant has made up any deficiency in the experience prescribed for the endorsement or endorsement desired and passed any necessary examination.”

Common questions

Does removing a limitation change my MMC expiration date?

No, not unless the applicant renews all endorsements that would appear on the MMC under § 10.227 of this part.

“will not change the expiration date of the mariner's MMC unless the applicant renews all endorsements that would appear on the MMC under § 10.227 of this part”

When do I have to surrender my old MMC after getting a new one?

If the old MMC is still valid at the time of application, the applicant must surrender it to the Coast Guard within 30 days of issuance of the new credential.

“If still valid at the time of application, the applicant must surrender the old, original credential to the Coast Guard within 30 days of issuance of the new credential.”

Can the Coast Guard change a limitation before I finish the required experience or exam?

No. The applicant must first make up any deficiency in the prescribed experience and pass any necessary examination.

“No limitation on any endorsement may be changed before the applicant has made up any deficiency in the experience prescribed for the endorsement or endorsement desired and passed any necessary examination.”

The text of 46 CFR 10.223

Electronic Code of Federal Regulations (eCFR), current as of April 16, 2026 · Read it on eCFR

Modification or removal of limitations or scope

(a) If the Coast Guard is satisfied by the documentary evidence submitted that an applicant is entitled by experience, training, and knowledge to an endorsement or increase in the scope of any MMC held, any limitations that were previously placed upon the MMC by the Coast Guard may be changed or removed. Such an increase in scope may include a change in horsepower or tonnage limitations, or geographic route restrictions.

(b) Modifications or removal of limitations or scope to MMC endorsement(s) under this section will not change the expiration date of the mariner's MMC unless the applicant renews all endorsements that would appear on the MMC under § 10.227 of this part.

(c) A complete application for modification or removal of limitation of scope must contain the following:

(1) A completed signed application;

(2) Proof that the mariner either holds a valid TWIC or has applied for a TWIC.

(3) All supplementary materials required to show that the mariner meets the mandatory requirements for the transaction sought:

(i) The mandatory requirements for officer endorsements are contained in part 11 of this subchapter.

(ii) The mandatory requirements for rating endorsements are contained in part 12 of this subchapter.

(iii) The mandatory requirements for tank vessel endorsements are contained in part 13 of this subchapter.

(iv) The mandatory requirements for STCW endorsements are contained in parts 11, 12, and 13 of this subchapter.

(4) The appropriate fee as set forth in § 10.219 of this part; and

(5) Any expired MMC held by the applicant. If still valid at the time of application, the applicant must surrender the old, original credential to the Coast Guard within 30 days of issuance of the new credential. If requested at the time of submission, the old MMC may be returned to the applicant after cancellation.

(d) No limitation on any endorsement may be changed before the applicant has made up any deficiency in the experience prescribed for the endorsement or endorsement desired and passed any necessary examination.

Sections it refers to

The plain-English explanation on this page was written with AI from the regulation text above and checked automatically before publishing: every quote appears in the text, every number comes from it, and a second model confirmed each statement adds nothing the text doesn't say. Regulation text current as of April 16, 2026. The regulation text governs. RegKnot is not affiliated with the U.S. Coast Guard.