The vast majority of the Navy submarine maintenance has occurred at public shipyards over the last decade, which, according to a recent Government Accountability Office report found, has only gotten the job done on schedule 11% of the time.

There are four public naval domestic shipyards that provide most of the maintenance on attack submarines and other nuclear-powered vessels: Portsmouth Naval Shipyard, Norfolk Naval Shipyard, Puget Sound Naval Shipyard, and Pearl Harbor Naval Shipyard. From fiscal 2016 through fiscal 2025, those four facilities took longer than planned for 89% of the time to complete depot-level maintenance on attack subs, according to the GAO report, which was released on Thursday.