Sunita Somvanshi
The Defense Department‘s costs for combat operations against Iran reached approximately $38 billion as of August 1, 2026. That number is significant — but it is not a complete accounting of all military and long-term costs, and the Congressional Budget Office noted it did not receive complete information from the Defense Department to give a final figure.
What CBO Found
The Congressional Budget Office released its Iran conflict cost assessment in mid-September 2026. Direct Department of Defense spending from February 28 through August 1 reached approximately $38 billion. That figure covers munitions expenditure, equipment losses, aircraft and base damage, additional flying hours, and fuel costs. CBO estimates that spending could increase by another $2 to $3 billion per month while the conflict continues, depending on the intensity of fighting.
For US taxpayers tracking the Iran war cost, the $38 billion figure is the most recent public estimate from the Congressional Budget Office covering DoD costs through August. It does not represent the total cost of the war or all US government spending on the conflict.
What the $38 Billion Does Not Include
The approximately $38 billion figure is not a final price tag for the Iran conflict. CBO’s estimate covers direct Department of Defense costs through August 1 and includes munitions, equipment losses, additional flying hours and fuel. It does not capture every future cost, including some reconstruction costs and longer-term personnel and healthcare expenses. The monthly spending estimate also changes depending on the intensity of fighting.
Why the Cost Figures Look Different
Three separate numbers have emerged from the Iran conflict, and they measure different periods or methodologies.
Defense Secretary Pete Hegseth put direct costs at approximately $37.5 billion in a July estimate — a different reporting date and potentially different scope than the CBO assessment. The CBO assessment covers February 28 through August 1 at approximately $38 billion. Earlier Pentagon assessments cover shorter windows from the conflict’s opening phase.
These numbers reflect different dates and measurement bases rather than conflicting estimates. A reader who encounters all three and assumes they describe identical scopes will get the wrong picture. The correct read is that they are snapshots from different points in the same conflict.
The CBO's Own Data Limitation
The CBO report noted that the Defense Department did not provide all the information CBO requested for its assessment. That limitation means the $38 billion is the best available public estimate — not a verified and complete accounting of wartime spending. The missing information means the estimate carries uncertainty and should not be treated as a complete accounting of DoD conflict costs.
The Interceptor Inventory Problem — Separate From Dollar Cost
Beyond direct spending, CBO estimates that between half and two-thirds of certain US missile-defense interceptor inventories have been consumed since June 2025, including use connected to the broader regional conflict and the February 2026 war with Iran. Replenishing those stocks, CBO says, could take at least five years.
This is a separate problem from the dollar cost of the war. Missile interceptors are not restocked on a short timeline. The depletion began well before the February 2026 conflict and continued through August 2026. The United States could formally conclude the conflict today and still face a multi-year window during which its missile-defense capacity would be reduced. For anyone tracking US Iran war military losses, this interceptor inventory is the metric with longer-term consequences.
Earlier reporting by Karmactive covered the Pentagon watchdog’s findings on damaged aircraft and bases from the conflict’s opening phase. The CBO’s September assessment updates and expands that picture.
What $2–3 Billion Per Month Actually Means
CBO’s monthly cost projection is a range rather than a fixed number. Lower-intensity periods cost less. Escalation costs more. The $2–3 billion figure is a planning estimate, not a monthly invoice. It also excludes base reconstruction and longer-term personnel and healthcare costs that typically follow military engagements.
Inflation Effects
Conflict spending at this scale affects defense procurement costs, energy markets and broader US inflation. The CBO noted that the war is expected to contribute to inflation into the first quarter of 2027, making inflation roughly 0.5 percentage points higher than previously estimated, driven largely by the reduction of oil and natural gas shipments through the Strait of Hormuz and disruptions to shipping through the Red Sea.
The CBO noted that its assessment was limited because the Defense Department did not supply all requested information. That represents an unusual position for a congressional oversight body — indicating that the executive branch limited what could be measured for public accountability.
FAQ
How much has the Iran war cost the US? The Congressional Budget Office estimates the US Department of Defense spent approximately $38 billion in direct costs from February 28 through August 1, 2026. This covers munitions, equipment losses and operational expenses. It does not include all reconstruction costs or longer-term effects. CBO noted its assessment was limited because the Defense Department did not provide all requested information.
How much does the Iran war cost per month? CBO estimates the conflict could cost $2 to $3 billion per month while fighting continues. The actual figure depends on the intensity of operations. Lower-activity periods cost less; escalation increases monthly spending. Base reconstruction and long-term personnel costs are not included in this estimate.
What US military equipment was lost or depleted? CBO estimates that between half and two-thirds of certain US missile-defense interceptor inventories have been consumed since June 2025, including expenditure connected to the broader regional conflict and the February 2026 Iran war. Replenishing those stocks could take at least five years. Aircraft and base damage costs are included in the $38 billion estimate.
How does the $38 billion figure compare to other cost estimates? Defense Secretary Pete Hegseth estimated approximately $37.5 billion in direct costs as of July 2026. The CBO figure covers February 28 through August 1. The two estimates use different measurement periods and possibly different methodologies. Earlier estimates cover shorter windows from the conflict’s opening phase. All are valid estimates for their respective time periods; they do not contradict each other.
