Norfolk, Portsmouth, Puget Sound, and Pearl Harbor, are the four entirely domestic military naval shipyards. Newport News, the General Dynamics yard in Groton,

Norfolk, Portsmouth, Puget Sound, and Pearl Harbor, are the four entirely domestic military naval shipyards. Newport News, the General Dynamics yard in Groton, and Ingalls Shipbuilding are effectively domestic-military-only shipbuilders. Some commercial shipbuilders, notably NASSCO, do business with the US Navy for smaller classes of ship as well as auxiliary vessels, and potentially could take orders from foreign militaries. But yes, there is a massive domestic shipyard and shipbuilding industry in the US that is military-only. There are almost 300 active ships and another 170 in the reserve fleet, almost all with far more complex maintenance requirements than the typical civilian vessel. Like many government operations, the US government doesn't try to oversee day-to-day operations, and awards those by contract. Same with the operation of national labs, for example.