Space Force Gen. Michael Guetlein, the program’s leader, said the CBO report released Wednesday relied on outdated cost estimates for existing technology and didn’t account for the missile shield’s undisclosed mix of technology and weapons.

“They did not estimate the architecture that we're building. Why is that? Well, first of all, they didn't come and ask us what we're building,” Guetlein said Thursday morning during the Inside the Dome event in Washington, D.C. “More importantly, we have not been putting a lot of information out in the public [about] exactly what we're doing, because the intelligence threat is so high.”

CBO officials declined to comment when asked whether they reached out to Guetlein, the Pentagon, or the Golden Dome office when working on the report.

The report says its $1.2 trillion estimate is based on the Golden Dome vision laid out in a January 2025 executive order, which President Trump said would cost about $185 billion: “Because DoD has not provided details about its objective architecture for GDA, CBO used the language in the executive order as a guide to determine what components to include in its notional NMD [national missile defense] system.”

Earlier CBO reports have indicated that the Defense Department, under the Trump administration, has not responded to researchers’ requests for information.

 A Golden Dome spokesperson told reporters after Guetlein’s public comments that the general is looking for ways to reduce costs by using artificial intelligence and existing technology.  she declined to provide details.

“You can't just take what we've done in the past and multiply it forward, or you're going to get large numbers like CBO got,” Guetlein said during the event.

During a subsequent panel, Rep. Jeff Crank, the head of the all-Republican Golden Dome Caucus, criticized the CBO’s estimates and claimed the nonpartisan research agency’s findings would be used by political enemies of the president. 

“I think it's very unfortunate that it came out,” Crank, R-Colo., said. “Some of the folks that are opposed to Golden Dome for whatever reason, for whatever political reason, they can continue to bury their heads in the sand…and they will use the CBO support as a wedge, as a tool, to say, hey, look, we can't afford this. But I think, as a country, we've got to confront this.”

When asked what the biggest threat to Golden Dome is, Rep. Mark Messmer, R-Ind., agreed it was politics, but said he was optimistic the program could get support across the aisle.

“It's unfortunate that, I mean, because it's the president's idea, we have people that object and fight it just because of that,” Messmer said. “But we've got to be consistent, we've got to continue to make the real threat deterrence that our country faces.”

CBO’s two-decade estimate is larger than the nearly $80 billion the administration plans to spend in the Golden Dome for America account over the next five years. But, so far, the missile defense program has been backed through heavily partisan reconciliation funding measures. 

Golden Dome netted $24 billion in Congressionally-approved reconciliation funds in last year’s budget, and another $17 billion has been requested through the same method this year. 

Guetlein acknowledged that it’s unclear what future funding and final size of the project will look like, but said components of the system will still be necessary for homeland security. 

“No matter what we look like, no matter how we're organized, no matter how well we are or not funded, the threat is not going away,” he said. “So when you start talking about longevity, we're here to stay. You may call me something different next month, or you may rewicker some of the funding, but we're here to stay because we have to protect the homeland.”