How many months after its expiration date may a Coast Guard credential be renewed without retaking the complete exam?

Correct Answer: Option C — 12 months

Per 46 CFR 10.227, a Merchant Mariner Credential may be renewed up to 12 months after its expiration date without requiring the mariner to retake the complete examination. Beyond this one-year grace period, the mariner must typically re-qualify through the full examination process to demonstrate current competency for the requested endorsement.