The Congressional Budget Office estimated Tuesday that a national missile defense system matching President Donald Trump’s January 2025 executive order would cost about $1.2 trillion over 20 years, more than six times the $185 billion the Pentagon’s own Golden Dome program director has publicly cited.

🚨 #BREAKING:

🇺🇸 Trump’s “Golden Dome” anti-ballistic missile defense system will cost $60B/year over 20 years, a total of $1.2T. pic.twitter.com/k3TYgexr6c

— OSINT Monitor (@sintmonitor) May 13, 2026

The nonpartisan analysis, requested by Sen. Jeff Merkley, the ranking member of the Senate Budget Committee, was built from the executive order’s language because the Department of Defense has not released details of its planned architecture for the Golden Dome for America (GDA) program.

The CBO’s four-layer notional architecture centers on a constellation of 7,800 space-based interceptors (SBIs) in low Earth orbit, three Ground-Based Midcourse Defense sites armed with Next-Generation Interceptors (NGIs), four Aegis Ashore facilities equipped with SM-3 Block IIA interceptors, and 35 regional sectors deploying Terminal High Altitude Area Defense (THAAD), SM-6 Block IB, and Patriot interceptors.

The SBI layer alone accounts for $743 billion, about 60% of the total, at $22 million per satellite with five-year service lives driven by atmospheric drag in low Earth orbit.

The Congressional Budget Office (CBO) is out with a new estimate of the cost of Golden Dome: $1.2 trillion. That’s about twice its estimate last year ($542 billion). About 70% of acquisition cost and 60% of total cost is for space-based interceptors.https://t.co/yetF2MYsY4 pic.twitter.com/XbcdapbD4Y

— Marcia Smith (@SpcPlcyOnline) May 12, 2026

The CBO’s figure may never be reached. Space Force Gen. Michael Guetlein, the GDA program director, told lawmakers in April that “if we cannot do it affordably, we will not go into production” on boost-phase SBIs. Removing the layer would reduce the 20-year cost to $448 billion, the CBO calculated, but would put the program out of compliance with the executive order that specifically mandated them.

Todd Harrison of the American Enterprise Institute (AEI) said the pricing gap tells a clear story. “The administration is not actually building what the executive order described,” he said.

Guetlein disputed outside cost models at a defense conference in Arlington, Virginia, in March, saying analysts “are estimating the modernization or the continuation of the legacy systems that we already have.”