WASHINGTON — The Defense Department’s Golden Dome Office has repeatedly refused requests from the Congressional Budget Office (CBO) for a briefing on its plans, a senior CBO official said today amid criticisms from the Pentagon that the watchdog organization’s $1.2 trillion cost estimate for the missile shield is based on inaccurate information.
“We have, to date, not been able to talk to the Golden Dome Office,” David Mosher, head of the CBO National Security Directorate, told the Brookings Institution. “We’ve asked them for briefings, and we have not gotten any. They’ve not been willing to do so. So, I know nothing about what they’re actually building.”
Golden Dome leadership and the CBO have been publicly at loggerheads over the cost of the sprawling missile defense program — each citing cost estimates that are hundreds of billions of dollars apart.
Mosher stressed that, as noted in the CBO’s May report, the two offices aren’t counting exactly the same thing: CBO’s tasking was to look at implementing the White House’s original executive order, while the Golden Dome office is projecting current spending plans. Thus, he said, it is unlikely a DoD briefing would change CBO’s analysis.
“And remember, we were not costing what the Golden Dome Office is building,” he added. “We were trying to estimate what the cost of the executive order.”
A spokesperson for the DoD Golden Dome Office run by Space Force Gen. Michael Guetlein did not return a request for comment by press time.
President Donald Trump issued his “Iron Dome for American” executive order in January 2025, which called for nation-wide defense “against ballistic, hypersonic, advanced cruise missiles, and other next-generation aerial attacks from peer, near-peer, and rogue adversaries.” The program was quietly renamed Golden Dome for America in February to avoid confusion with Israel’s much more limited Iron Dome missile defense system.
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CBO’s budgetary review of a “notional national missile defense system,” designed to fulfill Trump’s stated plan, found that it could cost up to $1.2 trillion to develop, deploy and then operate the system for two decades.
Since the study’s release Guetlein, the Pentagon’s Golden Dome czar, repeatedly has criticized those cost estimates — saying they were based on old technology and incorrect assumptions about the planned architecture.
“Those cost estimates are not estimating what we are building,” he told the annual Army Space and Missile Defense Symposium in Huntsville, Ala., on Aug. 11.
Trump originally put the price tag at $175 billion for the shield. Guetlein in April said the costs had risen slightly to $185 billion to deploy over the next decade, with the bump up necessary to speed fielding of several foundational space systems.
The administration’s fiscal 2027 budget request includes $17.5 billion for Golden Dome, but only some $400 million is in the Pentagon’s base budget with the rest in reconciliation funding.
CBO’s report notes that the FY27 budget documents show an average cost of about $15 billion per year for the rest of Golden Dome’s five-year spending plan, consistent with the $185 billion price tag.
Thus, the report concludes, “DoD’s stated cost appears to cover a shorter time frame than CBO’s analysis and may reflect a different scope of activities and budget categories. Even so, that stated cost is far lower than CBO’s estimate for a notional NMD [national missile defense] architecture consistent with the ‘Iron Dome’ executive order. That difference suggests either that GDA’s objective architecture is more limited than CBO’s notional NMD system or that DoD expects significant funding from other accounts to contribute to GDA (or both).”
CBO isn’t the only congressional office to experience DoD’s reluctance to provide information about the planned Golden Dome architecture.
Numerous members on both sides of Capitol Hill, and perhaps more importantly both sides of the aisle, have been fuming about unanswered questions surrounding the Pentagon’s plans. These include: details about the various weapon systems involved, especially new space-based interceptors that even Guetlein has admitted may not be affordable; where Golden Dome assets would be deployed and what areas of the United States would be covered; how much money is going to each piece of the multi-faceted shield; and which budget pots, including individual service budgets, are being tapped to pay for what.