U.S. Spending on the Iran War Hit $38 Billion, CBO Says
The United States had spent about $38 billion on the war with Iran as of Aug. 1, 2026, the Congressional Budget Office estimated in a report published Sept. 15. CBO
That estimate covers a war that was more than six months old in September 2026. Times of Israel The CBO put the burn rate, or pace of future spending, at $3 billion for each additional month, depending on intensity. The Guardian
A separate Pentagon inspector general review, cited in the CBO assessment, put total spending at $33.4 billion, with $22.3 billion for munitions alone through June 30. Munitions means weapons that are fired or launched. The review found strategic inventory shortfalls, meaning stockpiles fell below planned levels, and industrial base bottlenecks, meaning factories cannot produce replacements fast enough.
Replacement is the largest part of the bill. The CBO calculated $21.7 billion is needed to replace weapons used so far, including $13.1 billion for missile defense interceptors alone. Interceptors are defensive missiles fired to knock down incoming missiles, like emptying a pantry faster than stores can restock it. Patriot and Standard Missile interceptors cost roughly $4 million each, while THAAD interceptors cost roughly $12 million each. Rebuilding the U.S. stockpile of defensive missiles would probably take at least five years, even if production was increased.
Costs were not only financial. The CBO found Iranian strikes damaged or destroyed hundreds of buildings and structures at U.S. bases in Kuwait, Bahrain, Qatar, the United Arab Emirates, Saudi Arabia, Iraq, Oman and Jordan. The United States keeps bases spread across those countries, and fixed structures are exposed to long-range attack.
Effects reached beyond the defense budget. Brent crude, the global benchmark for oil prices, rose from $64 a barrel before the fighting to $103 at its peak. The CBO projects inflation will run 0.5 percentage points higher than expected by early 2027.
The report was requested by Rep. Brendan Boyle, ranking member of the House Budget Committee. The ranking member is the senior lawmaker from the minority party. The CBO said it built its estimates largely from public reporting because the Pentagon did not respond to its requests for information.
Looking at what this means for sustainment and oversight, the numbers describe a missile-centered war with an uneven cost exchange. Each defensive shot costs $4 million to $12 million. That pace of interceptor use creates a budget and supply limit different from ordinary strike weapons, especially with a five-year rebuild timeline and factory limits on resupply.
The broader context here is stockpile depth against factory output. Shortfalls tied to Iran do not stay in one theater. They affect choices about other U.S. commitments, what gets bought and when, and how long high-tempo defense can continue. A $3 billion monthly figure gives Congress a clear baseline for extra funding bills, shifts in existing funds, and decisions about stockpile risk if factories cannot speed up while fighting continues.
