US Navy Submarine Maintenance Backlog Could Cost Billions, GAO Warns
- Severe maintenance delays and shipyard capacity constraints could leave more than a dozen US Navy attack submarines sitting idle for thousands of days through the end of the...
- The latest findings highlight a compounding financial and readiness burden for the US Navy.
- The GAO report points to the Los Angeles-class submarine USS Pasadena as a primary example of the systemic bottlenecks.
Severe maintenance delays and shipyard capacity constraints could leave more than a dozen US Navy attack submarines sitting idle for thousands of days through the end of the decade, according to a Government Accountability Office report. The congressional watchdog found that 15 submarines awaiting decommissioning could rack up over 14,000 days of inactive idle time from fiscal year 2026 through fiscal year 2030, resulting in more than $3 billion in costs to operate and support vessels that provide no operational capability.
Submarine Backlogs Cost Billions in Operational Support
The latest findings highlight a compounding financial and readiness burden for the US Navy. Over the past 10 years, the sea service has lost more than 15,000 operational days due to maintenance delays and idle time on active attack submarines, according to the GAO. Those delays cost an estimated $3.4 billion to sustain crews and submarines that remained sidelined before entering official maintenance cycles. Active idle time occurs when a vessel is no longer certified to operate but has yet to begin shipyard work. During this phase, the Navy continues spending hundreds of thousands of dollars daily for submarines to sit pier-side. A related backlog for inactive submarines is now generating a separate multi-billion-dollar cost stream as public shipyards struggle to keep pace with demand.
The Case of the USS Pasadena
The GAO report points to the Los Angeles-class submarine USS Pasadena as a primary example of the systemic bottlenecks. The vessel entered inactive idle status on January 1, 2025, but is not scheduled for decommissioning until November 15, 2028, constrained by limited capacity at public shipyards. While the Navy informed the GAO that it plans to use the USS Pasadena as a training platform during the multi-year wait, the delay will ultimately cost the service over $300 million, according to the watchdog. Nuclear-powered submarines require extensive maintenance, repairs, and final decommissioning at specialized public shipyards, though a limited amount of depot-level work can be handled by private yards.
Proposed Mitigations and Industry Capacity
To address the mounting backlog, the Navy and domestic shipbuilders are exploring several revitalization efforts, including workforce investments and infrastructure upgrades. President Donald Trump issued an executive order directing the Navy and the Department of Defense to establish a fifth public shipyard to boost nuclear-powered submarine and aircraft carrier readiness. In the interim, the GAO noted that the Navy is evaluating alternative strategies, such as defueling nuclear reactors while attack submarines are pier-side rather than waiting for dry dock availability. However, the watchdog stated that naval officials were unable to provide documentation of detailed analyses regarding the feasibility and cost-effectiveness of that approach. Additional proposals under review include utilizing floating dry docks, transferring inactive crews to active vessels, and extending submarine service lives, though those service life extensions remain pending formal approval.
