WASHINGTON — A “notional national missile defense system” akin to President Donald Trump’s signature Golden Dome missile shield project could cost up to $1.2 trillion to develop, deploy and then operate for two decades, according to a new estimate published by the Congressional Budget Office.
CBO said most of the cost, over $1 trillion, would be needed for acquisition, including “costs for the system’s major components — namely, the interceptor layers and a space-based missile warning and tracking system.”
“The most expensive component is the space-based interceptor layer, which accounts for about 70 percent of acquisition costs and 60 percent of total costs,” the report says.
The office acknowledged that since the Department of Defense has publicly released few details about the underlying architecture of the actual Golden Dome project, it’s “impossible to estimate the long-term cost of the GDA [Golden Dome for America] system being contemplated by DoD.”
“In the absence of specific plans for GDA’s objective architecture, CBO has estimated the cost of a notional NMD architecture based on the defensive systems and capabilities that are called for in the executive order,” it says, referring to Trump’s January 2025 EO calling for what was then referred to as Iron Dome for America.
Based on the EO, CBO said the system it evaluated would “have the capacity to fully engage an attack mounted by a regional adversary (that is, one with limited capabilities, such as North Korea) or a small-scale attack mounted by a peer or near-peer adversary (one with military capabilities similar to those of the United States, namely Russia or China).
“However, the system could be overwhelmed by a full-scale attack mounted by a peer or near-peer adversary. Furthermore, ‘fully engage’ is not the same as ‘fully defeat’ because no defense works perfectly every time,” it said.
Voyager is fortifying the U.S. Defense supply chain
Answering the Pentagon’s call to bolster defense industrial base.
The CBO’s estimate is the latest in an ever-growing pricetag for the sprawling missile shield. In May 2025, President Donald Trump said the program would cost $175 billion, presumably to initially deploy. Last month, Golden Dome program manager Gen. Michael Guetlein told lawmakers the cost to stand up Golden Dome would come in around $185 billion.
CBO said the DoD’s estimates appear to be in line with budget projections. However, the report says, “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 architecture consistent with the ‘Iron Dome’ executive order.”
A Pentagon spokesperson declined to comment for this report beyond pointing to April testimony by Guetlein before lawmakers in which he took issue with outside estimates of Golden Dome’s eventual cost. He said that previous public calculations were “not estimating what I’m building. They are estimating the modernization or the continuation of the legacy systems that we already have and they just take the cost of a legacy system and they multiply it out and they get these really large numbers and they say, well, that must be it. That is not what Golden Dome is doing.”
Golden Dome, he said, is “doing business differently” with different acquisition authorities, strategies and efficiency measures.
Still, he appeared to be cognizant of price tag concerns, and told lawmakers that the Pentagon would not pursue space-based interceptors for boost-phase interception of missile threats if it didn’t make financial sense.
“Because we are looking at the threats from a multi-domain perspective to make sure I have redundant capabilities and I don’t have single points of failure,” he said. “So, if boost-phase intercept from space is not affordable and scalable, we will not produce it, because we have other options to get after it.
“We are so focused on affordability. If we cannot do it affordab[ly], we will not go into production,” he said.
UPDATED 5/12/2025 at 4:42pm ET to include more context of Guetlein’s April testimony.