US Navy backlogs could leave over a dozen submarines sitting idle for years, costing $3 billion, watchdog says

The USS Pasadena entered idle status in January 2025 but isn't scheduled for decommissioning until November 2028.

US Navy photo by Mass Communication Specialist 1st Class Alfred Coffield/Released The Navy's maintenance problems are creating a growing backlog of submarines awaiting decommissioning.

15 subs could spend 14,000 days idle through 2030, costing the Navy more than $3 billion.

The GAO says the Navy hasn't fully evaluated options that could reduce the backlog.

Severe backlogs could leave over a dozen US Navy attack submarines awaiting decommissioning sitting idle for more than 14,000 days through the end of the decade, and cost the sea service over $3 billion, according to a new watchdog report.

Navy maintenance delays have already cost the sea service billions of dollars and sidelined active attack submarines for thousands of operational days, affecting fleet readiness .

A new report from the Government Accountability Office, a congressional watchdog, said: "Over the last 10 years, the US Navy has lost more than 15,000 operational days due to maintenance delays and idle time on active attack submarines .

These delays resulted in an estimated $3.4 billion in costs to sustain crews and submarines that provided no operational capability." Idle time for active submarines refers to the period when a vessel is no longer certified to operate but has yet to enter maintenance.

The Navy may still end up paying out hundreds of thousands of dollars a day for submarines to sit pier-side.

A related backlog for inactive subs is expected to be another substantial cost burden.

"Without mitigation, 15 attack submarines will enter inactive idle time from fiscal year 2026 through fiscal year 2030," the new GAO report said, "during which time the Navy could incur more than 14,000 days of inactive idle time and $3.1 billion in costs to operate and support these inactive submarines." Public yards are stretched thin for maintenance and repairs of submarines.

Daniel DeAngelis/Norfolk Naval Shipyard The report cited the Los Angeles-class sub USS Pasadena as an example.

The vessel, which entered inactive idle status on January 1, 2025, is not scheduled for decommissioning until November 15, 2028, due to limited shipyard capacity.

The Navy told the GAO that it will use the Pasadena as a training platform while it waits for decommissioning; however, the delay will cost the service over $300 million, the GAO said.