USNS

USNS stands for United States Naval Ship, a prefix used for certain ships of the United States Navy that are not commissioned as warships. These ships are operated by the Military Sealift Command and crewed mainly by civilian mariners under contract to the U.S. government. Unlike commissioned ships, which carry the USS prefix and are crewed by Navy personnel, USNS vessels remain civilian-manned, though they may temporarily host Navy personnel for specific missions and can be assigned Navy mission commanders.

USNS vessels perform a range of support roles to the Navy's combat forces, including cargo and fuel transport, fleet replenishment, prepositioning of equipment, ocean surveillance and research, and medical support. Hospital ships Mercy and Comfort are among the best-known USNS ships and have been deployed for humanitarian missions and disaster response. Other families include logistics ships, ocean-going tenders, and other support ships designated with hull classifications such as T-AKE, T-AO, and T-AH.

Operational control remains with the U.S. Navy for mission objectives, but day-to-day operations are run by the MSC and civilian crews. The prefix is a reminder that while these ships serve naval needs, they are not warships in the commissioned sense. The USNS designation originated with the former Military Sea Transportation Service; the organization was renamed to Military Sealift Command in 1970, after which ships commonly used the USNS prefix.