The Coast Guard of the United States of America (USCG) has published a very useful new resource on their website that provides extensive information about the Maritime Mobile Service Identity (MMSI) that is used in digital selective calling (DSC) radios and also in automatic identification system (AIS) transmitters. At this writing the information is located at
https://www.navcen.uscg.gov/maritime-mo ... e-identity
The general navigation path to this resource on the USCG NAVCEN website is
Home--> Maritime Safety Information---> Maritime Telecomms--> MMSI
Also mentioned in the above resource is another very useful new collection of information that gives a tabular listing of blocks of MMSI numbers provided to USA boaters and shows the MMSI-issuing authority that issued those blocks. At this writing the information is located at
https://www.navcen.uscg.gov/sites/defau ... tments.pdf
There is a simple general rule regarding identifying what issuing-authority may have issued an MMSI for a USA vessel: All MMSI's issued by the Federal Communications Commission (FCC) end in zero, including VHF handheld MMSI's.
ASIDE: the reason for a preference to have the MMSI end in a zero is because an MMSI of one-digit-shorter or in some cases two-digits-shorter was used in some earlier legacy selective-calling satellite communication systems of other selective calling long-range communications systems, so preserving the ending-in-zero MMSI numbers in the USA allows them to be better allocated to commercial vessels that may be still using these satellite or long-range radio communication systems with selective calling.