CBO says Trump’s Golden Dome missile shield could cost $1.2 trillion over 20 years

The Congressional Budget Office estimates that developing, deploying and operating the Golden Dome missile defense system would cost roughly $1.2 trillion over the next 20 years, far exceeding figures previously cited by the Trump administration.

In a 12-page report released on Tuesday, the CBO said procurement costs for the national missile defense system alone would exceed $1 trillion. The report said the estimate covered funding for interceptor layers, a space-based missile warning and tracking system, research and development efforts, and improvements to system integration and performance.

The CBO said the space-based interceptor layer would account for roughly 70% of procurement costs and about 60% of the system’s overall cost.

General Mike Guetlein, director of the Golden Dome for America office, said in March that the missile defense system would cost $185 billion.

Congressional Republicans have already allocated $25 billion for the project under President Donald Trump’s “One Big, Beautiful Bill,” which he signed into law last July.

The Pentagon is also seeking an additional $17 billion from Congress for the project as part of the reconciliation process. Defense Department officials said last month that $750 billion of the Trump administration’s record $1.5 trillion defense budget request for fiscal year 2027 would be directed toward missile defense systems, drones, artificial intelligence and strengthening the defense industrial base.

The new report said the wide gap between Guetlein’s estimate and the CBO’s calculations suggested that the Pentagon’s planned system architecture “may be more limited than the target architecture.”

It also said the discrepancy could stem from the Defense Department’s expectation that “significant funding from other budget accounts” would support the system. The CBO said both explanations could be valid simultaneously.

In the administration’s fiscal 2027 budget request, the Golden Dome system was described as a “layered homeland defense” against threats from US adversaries. The budget document said the system “keeps Americans safe while leveraging innovative program management and procurement approaches to responsibly steward taxpayer resources.”

The CBO report, however, said that while the missile defense system would be “far more capable” than the capabilities currently available to the US, it “would not be an impenetrable shield or negate the effects of a large-scale attack of the kind that Russia or China could launch.”

The report also said the national missile defense system could “deter or defeat smaller attacks by a peer adversary,” which would likely form part of a regional conventional conflict.

At the same time, the report warned that such a system could also encourage a peer adversary to expand the scale of those attacks.

The CBO prepared the report at the request of Senator Jeff Merkley of Oregon, the senior Democrat on the Senate Budget Committee.

Merkley said on Tuesday that the CBO’s findings showed the Golden Dome was “nothing more than a massive transfer of resources to defense contractors, funded entirely by taxes paid by working Americans,” and that the system “would do little to advance American national security.”

The Oregon Democrat added: “I will continue working with my colleagues in the Senate to prevent another penny from being poured into this scheme.”