Vessels sailing under the Northern Mariana Islands Country Flag are required to have on board this flag as part of flag state requirements that derive from maritime regulations in the International Code of Signals and the International Safety Management (ISM) Code. These codes are published by the International Maritime Organization (IMO) as an ongoing effort to reinforce maritime safety procedures and communications to the international maritime community. Fleet management companies and ship owners are responsible to ensure that each vessel in their respective fleets have the appropriate flag signage onboard to be in compliance. This flag is used to identify the flag state a vessel is sailing under and to communicate with other vessels under the provisions of the International Code of Signals.
In 1972, the Third Marianas Legislature held a flag design contest for Marianas schools. The winning submission was designed by Rotanese student Vito Calvo and featured a latte stone and star on a field of blue.
The flag was not officially adopted until July, 4 1976.
In 1981, the flag was modified and the mwáár (traditional flower wreath) was added. This version of the flag was officially adopted in July, 1985.