How Much Military Spending Can Congress Approve?

Now that a memorandum of understanding is in place and the Strait of Hormuz is open for business again, policymakers will start to assess the cost of the war in Iran and make plans for military spending.  

The Trump administration already announced in January 2026 that it wanted to spend a record-breaking $1.5 trillion on defense in 2027. In its April budget request, the White House specified that it envisioned two bills to fulfill its request to Congress for defense spending. The first would be the regular FY 2027 Department of Defense Appropriations bill to total $1.154 trillion, and the second would be an emergency, one-time $350 billion mandatory appropriations bill.   

President Trump's FY 2027 Defense Spending Request  

Regular Appropriated Spending	$1.154 Trillion
Mandatory Supplemental Appropriations	$350 Billion
Total Defense and Security Spending	$1.504 Trillion

The President’s plan represents a massive increase in defense spending. Compared to last year’s appropriated funds for defense, President Trump’s goal of $1.504 trillion in defense spending is $601 billion more for the military than in 2026, representing a funding hike of 66% in one year. Even if the emergency $350 billion were excluded, regular defense and security appropriations would increase by $251 billion, or 28%, under the White House proposal (table below).  

Where Does Spending on Iran Operations Fit?  

It is still not 100% clear whether the White House views extra spending for the war in Iran as a part of the $1.5 trillion or in addition to that request. Adding extra dollars for Iran operations above the $1.5 trillion goal would further complicate a difficult task. For that reason, most lawmakers anticipate that whatever money is requested for Iran war operations will come from the $350 billion supplemental mandatory appropriations.

Emergency Supplemental Debate Could Start Soon

Now that a memorandum of understanding with Iran has been signed, it should kick off the process of requesting and drafting the military supplemental spending bill. Democrats will be inclined to oppose any funding request from President Trump in the coming months, but there was zero chance that they would negotiate while hostilities were still underway in Iran. 

The first option for Republicans is to try and use the partisan budget reconciliation process this summer to pass the mandatory spending. There is however, growing pessimism on the Hill that another reconciliation budget can pass given the difficulty of the last funding bill. Failing reconciliation, Republicans could force a vote and use the military funding as political pressure against Democrats heading into the midterms. 

Congressional Appropriation Process Is Gridlocked  

At this point, it is unlikely that Congress will even try to fund the President’s initial request for $1.154 trillion in regular appropriations before the election. House Republicans unveiled a $1.072 trillion defense appropriations bill last week, to which Democrats have already objected. It is clear that a large increase in spending for defense appropriations would have to be tied to big spending hikes for non-defense programs to garner necessary Democrat votes. That kind of deal would be particularly difficult to forge in the current political climate and right before the midterm elections.  

As it stands, the regular appropriations process is at a standstill. We believe that Congress will head into September once again needing a Continuing Resolution (CR) to fund the government at current levels to avoid a government shutdown. If Congress can pass a CR to keep the government open, it will likely extend past the November elections and into a holiday lame duck period. This means that the decision on how much more money defense gets through regular appropriations will probably have to wait until after Thanksgiving.  

Projecting Spending Totals for Defense in 2027 

Washington is waiting for the White House, Department of War, and Office of Management and Budget to submit a specific request for emergency mandatory appropriations. Since this money will include Iran funding and exclude non-defense priorities, Democrats will probably oppose the measure. The White House will likely need unanimous GOP support, including Republican budget hawks. We believe that will keep the total emergency military spending slightly below the $350 billion budget request. We predict the actual bill will be $150 billion to $250 billion if it gets a vote.  

With regard to regular, annual appropriations, House Republicans seem to have set the opening bid at $1.072 trillion. That number has been criticized by Democrats and will likely come down during a lame duck holiday deal.  

If Republicans can muster the votes for a third reconciliation bill, it seems likely that it would include anywhere from $150 to $250 billion in emergency mandatory appropriations. Otherwise, they will try to pressure Democrats to support a bipartisan military funding package ahead of elections. The regular appropriations will also need bipartisan support. That could drive that bill down from $1.072 trillion to the $950 billion - $1 trillion range.