The US Navy’s shipyard overhaul is projected to cost more than US$200 billion and take over 50 more years, the US Government Accountability Office (GAO) said on Friday, September 25.
The Shipyard Infrastructure Optimization Program (SIOP) was launched in 2018 to modernise the four public yards at Norfolk, Portsmouth, Puget Sound, and Pearl Harbor. These yards maintain the navy’s aircraft carriers and submarines, which are all powered by nuclear reactors.
GAO examined the navy’s funding instructions and planned work alongside cost assessments finalised by April 2026 at three of the four yards. The last currently planned projects are scheduled to finish after 2080 (the projection is not an approved navy programme baseline).
Portsmouth’s planned work alone was estimated at US$41.6 billion after costs were escalated over its potential construction period, the lowest of the three completed yard analyses.
The navy’s initial estimate for SIOP in 2018 was at least US$21 billion over 20 years.
GAO said in 2022 that estimates for the first three dry dock projects had increased by more than US$4 billion. The original SIOP estimate excluded inflation, utility spending, environmental cleanup, and historic preservation.
Planning and project development at each yard have taken more than eight years, longer than the navy expected.
GAO said environmental issues have added work at the yards, while seismic risks at Puget Sound require retrofits to dry docks and facilities. The first, covering roughly fiscal years 2026–2042, include dry docks and piers alongside an initial waterfront production facility at each yard. The second, running approximately from 2038 to 2079, covers further waterfront facilities and enabling work.
A third block, starting around fiscal year 2074 and continuing to the programme’s end, includes logistics complexes and specialised repair shops, along with other support facilities. Some dock and pier work is planned beyond the first block.
The yards must remain operational during construction. The navy said in its 2025 year-in-review that, since 2018, it had finished more than 50 facilities projects with a combined value of nearly US$1.5 billion. It also said more than 300 pieces of equipment for industrial plant use, valued above US$700 million, had been delivered, while about 50 further projects worth nearly US$7 billion were under contract.
Although SIOP uses elements of major defence acquisition oversight, GAO found that the navy has no set process for reassessing planned facilities against future fleet needs. It recommended periodic reviews of programme requirements and annual checks on mission readiness and affordability.
GAO also called for Program Management Office 555, working with Naval Facilities Engineering Systems Command, to document which entity manages SIOP projects.
The navy accepted each of GAO’s three recommendations and set out how it intends to carry them out.
The navy briefs Congress on parts of SIOP but is not required to provide a standard report on the entire programme’s costs and risks.
GAO proposed that Congress weigh a requirement for the navy to issue yearly reports showing spending and risks alongside changes to cost and schedule estimates
In June, the navy outlined a planned US$30 billion shipyard construction contract covering waterfront work, including a new multi-mission dry dock at Puget Sound. The figure is a ceiling for a potential 10-year procurement, rather than a separate estimate of SIOP’s total cost.
