CBO Estimates Trump’s Golden Dome Missile Defense Costs $1.2 Trillion Over 20 Years

The Congressional Budget Office estimated that a national missile defense system broadly aligned with President Donald Trump’s Golden Dome executive order could cost roughly $1.2 trillion over 20 years, far exceeding the Pentagon’s public estimate of about $185 billion.

“01:44 00:52 02:36 01:42 01:30 04:23 00:57 02:19 23:17 05:09 20 Minutes with AFP Published May 13, 2026 at 1:02 AM • Updated May 13, 2026 at 1:02 AM The anti-missile shield project desired by Donald Trump could cost far more than the estimates advanced by the president”

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Space-based interceptors, or SBIs, would account for about $743 billion of the total, according to the CBO report released May 12.

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The CBO said the interceptor satellites would need to be close enough to a launch location to engage within roughly three to five minutes in the case of an intercontinental ballistic missile, driving the need for a massive constellation.

To engage a salvo of 10 nearly simultaneous intercontinental ballistic missile launches, the CBO estimated about 7,800 interceptor satellites would be required, and maintaining that capability over two decades would require about 30,000 satellites in total.

The CBO also concluded that even its notional system could still be overwhelmed by a large-scale attack from China or Russia, while removing space-based interceptors would lower the 20-year estimate from $1.2 trillion to about $448 billion.

The CBO emphasized that its study was not based on a detailed administration blueprint because the Defense Department has not publicly released the architecture it intends to build, and that distinction highlighted a disconnect between Congress and the administration over the program.

Sen. Jeff Merkley, the ranking Democrat on the Senate Budget Committee, requested the report, and Military Times said the estimate was significantly more than the $185 billion the Trump administration set aside for the project in its proposed fiscal 2027 defense budget.

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Independent analyst Todd Harrison of the American Enterprise Institute said in an interview that “there is virtually no chance SBIs will be part of it beyond prototyping,” adding that “SBIs do not scale with the threat and do not have a cost per kill that is competitive with ground-based alternatives.”

The Pentagon official overseeing Golden Dome, Gen. Michael Guetlein, responded to Harrison by saying Harrison was not estimating the architecture the Pentagon intends to build, while Harrison speculated Guetlein appears to be working within a fixed budget ceiling rather than designing strictly around the executive order’s ambitions.

The CBO also warned that the notional system could be overwhelmed by a large-scale attack from China or Russia, reinforcing concerns already raised publicly by Guetlein about the affordability of orbital missile interceptors.

The CBO projected that the interceptor layer would account for roughly 70% of acquisition costs and about 60% of total system costs, and it said the interceptor layer’s scale and continuing need to replenish it were the central financial challenge.

“What is Trump's Golden Dome missile defense system”

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Time reported that Gen. Michael Guetlein testified that the program would cost $185 billion through 2035 for what he described as the system’s “objective architecture,” while the CBO used a much longer time horizon and estimated acquisition costs alone would exceed $1 trillion over 20 years.

Time also quoted Trump’s executive-order timeline, saying the President wanted the system operational before the end of his term in January 2029, and it described the space-based interceptors as a controversial and costly element of the proposal.

In response to the CBO release, Sen. Jeff Merkley called the project “nothing more than a massive giveaway to defense contractors paid for entirely by working Americans,” while the report’s framing in SpaceNews noted that removing space-based interceptors would sharply reduce the projected costs.

The CBO’s analysis further warned that “fully engage” is not the same as “fully defeat,” and that the system could be overwhelmed by a full-scale attack mounted by a peer or near-peer adversary.