USNS stands for United States Naval Ship. This is for non-commissioned ships like the hospital ships Comfort and Mercy.
USCGC stands for United States Coast Guard Cutter.
There is no USA as a ship name prefix.
WWG1WGA
Garde la Foi, mes amis! Nous nous sommes les sauveurs de la République! Maintenant et Toujours!
(Keep the Faith, my friends! We are the saviors of the Republic! Now and Forever!)
LonePalm, le Républicain du verre cassé (The Broken Glass Republican)
Bkmk
....”USS stands for United States Ship...USNS stands for United States Naval Ship.”....
Also: USS ships are manned by uniformed Navy personnel, USNS ships are manned by civilians (mostly government civilians with some ships having contract civilian crews). There are also a few hybrid USS ships with part of the crew that is civilian. These few are the exception.
Go Navy!/Pat