The Plain Record

Neutral daily news — clear headlines, complete facts.

On the Hill

CBO Estimates Iran War Costs at $2 Billion to $3 Billion Monthly

A CBO report estimates the war with Iran is costing $2 billion to $3 billion monthly and has likely depleted between one-half and two-thirds of key missile interceptor stocks.

Published September 15, 2026 at 4:12 PM EDT

The short answer

A CBO report estimates the war with Iran is costing $2 billion to $3 billion monthly and has likely depleted between one-half and two-thirds of key missile interceptor stocks.

CBO Estimates Iran War Costs at $2 Billion to $3 Billion Monthly

The Facts

Who
Congressional Budget Office (CBO), Rep. Brendan Boyle (D-PA), President Trump, and the Department of Defense.
What
Congressional Budget Office report on the costs and munitions impact of the Iran war.
When
Tuesday
Where
Washington, D.C.
Why
To assess the fiscal impact of the conflict and the resulting depletion of strategic missile inventories.

The Congressional Budget Office (CBO) reported on Tuesday that the ongoing conflict with Iran is costing between $2 billion and $3 billion per month. The nonpartisan agency estimated that direct costs reached approximately $38 billion between February 28 and August 1. These figures do not include the costs associated with repairing damaged U.S. bases in the region.

The report follows a period of heightened military activity, including an $87.6 billion supplemental funding request sent to Congress by the Trump administration in June. That request included $67 billion for Department of Defense needs related to the war. Congressional Republicans have since sought to provide up to $73 billion in new funding through the reconciliation process, though the budget blueprint remains stalled in the Senate.

According to the CBO, the high volume of interceptor missiles used to defend against incoming fire has reduced U.S. stockpiles. The agency estimates the U.S. has probably used between one-half and two-thirds of its inventory of munitions like Patriot and THAAD interceptors since June 2025. Replacing the munitions used through August 1 is expected to cost $21.7 billion, while replacing lost equipment, such as a $500 million THAAD air defense radar, will cost at least $1.9 billion.

The scale of munitions depletion affects the long-term readiness of the U.S. military. The CBO noted that the reduced inventory could take several years to replenish. The report stated this shortfall would be problematic if a conflict arose with an opponent possessing large missile arsenals, specifically mentioning China. While President Trump and Admiral Brad Cooper have stated the U.S. remains well-armed and ready for any contingency, a separate Pentagon inspector general report stated that the conflict has revealed "industrial base bottlenecks" for munitions resupply.

What happens next depends on congressional action regarding funding and the intensity of the combat. If the war continues at its current intensity, the $2 billion to $3 billion monthly cost will persist; however, another escalation like the one seen in July could drive monthly spending to $3 billion or higher. Legislatively, the $73 billion funding package remains stalled in the Senate. Additionally, if the Pentagon chooses to replace lost aircraft with newer models rather than exact replicas, the estimated cost for equipment replacement could rise from $1.9 billion to $3.3 billion.

Timeline of what happened

Key dates and decisions, in the order they occurred.

  1. June 2025

    U.S. begins using significant interceptor missile inventory

  2. February 28, 2026

    Start period for CBO direct cost estimate

  3. June 2026

    Trump administration sends $87.6 billion funding request to Congress

  4. July 2026

    War costs reach $3 billion for the month due to escalations

  5. August 1, 2026

    End period for CBO $38 billion direct cost estimate

Summaries are written by The Plain Record to state the facts of a story plainly and without political slant. Drafted with AI assistance and checked against the source record before publication. See how we report, or report a correction.

← Back to the front page

Questions readers ask

What happened: CBO Estimates Iran War Costs at $2 Billion to $3 Billion Monthly?

Congressional Budget Office report on the costs and munitions impact of the Iran war.

Who is involved?

Congressional Budget Office (CBO), Rep. Brendan Boyle (D-PA), President Trump, and the Department of Defense.

When did this happen?

Tuesday

Where did this happen?

Washington, D.C.

Why does this matter?

To assess the fiscal impact of the conflict and the resulting depletion of strategic missile inventories.