Military Sealift Command

The United States Navy's Military Sealift Command (MSC) is an organization that controls the replenishment and military transport ships of the Navy. Military Sealift Command has the responsibility for providing sealift and ocean transportation for all US military services as well as for other government agencies. It first came into existence on July 9th, 1949 when the Military Sea Transportation Service (MSTS) became solely responsible for the Department of Defense's ocean transport needs. The MSTS was renamed the Military Sealift Command in 1970.

Military Sealift Command ships are made up of a core fleet of ships owned by the United States Navy and others under long-term-charter augmented by short-term or voyage-chartered ships. The Navy-owned ships carry blue and gold stack colors, are in service with the prefix USNS (United States Naval Ship), rather than in commission (with a USS prefix), have hull numbers as an equivalent commissioned ship would have with the prefix T- and are primarily civilian manned by either civil service mariners or contract crews (see United States Merchant Marine) as is the case of the special mission ships. Some ships may have Navy or Marine Corps personnel on board to carry out communication and special mission functions, or for force protection. Ships on charter or equivalent, retain commercial colors and bear the standard merchant prefix MV, SS, or GTS, without hull numbers.

Eight programs compose Military Sealift Command: Fleet Oiler (PM1), Special Mission (PM2), Strategic Sealift (PM3), Tow, Salvage, Tender, and Hospital Ship (PM4), Sealift (PM5), Combat Logistics Force (PM6), Expeditionary Mobile Base, Amphibious Command Ship, and Cable Layer (PM7) and Expeditionary Fast Transport (PM8).

MSC reports to the Department of Defense's Transportation Command for defense transportation matters, to the Navy Fleet Forces Command for Navy-unique matters, and to the Assistant Secretary of the Navy (Research, Development and Acquisition) for procurement policy and oversight matters.