46 CFR §154.1803

1. (a)A Certificate of Compliance expires after a period not to exceed twenty-four months from the date of the examination under § 154.150.
2. (b)If a vessel's IMO Certificate of Fitness expires or otherwise becomes invalid, its Certificate of Compliance becomes invalid for the carriage of cargoes listed in Table 4 of this part or authorized by special approval under § 154.12. To maintain the validity of the Certificate of Compliance, the vessel's owner must submit a copy of any revised or reissued IMO Certificate to Commanding Officer, Marine Safety Center.