The United States spent $874 billion on national defense in fiscal year (FY) 2024 according to the Office of Management and Budget, which amounted to 13 percent of federal spending. Defense spending in FY 2024 was less than the average for the last decade, which was 14 percent of the budget. Such spending indicates that lawmakers have prioritized national defense as a key part of our budget; indeed, the United States spends more on defense, relative to the size of its economy, than any other member of the G7 (a group of the world’s largest advanced economies, the members of which are shown in the chart below). This explainer looks at the components of the U.S. defense budget.
How is Defense Spending Distributed?
The majority of the overall defense outlays, $826 billion in FY2024, was spent by the Department of Defense (DoD) on military activities. The remaining $47 billion was spent on defense-related activities carried out by other agencies, such as the Department of Energy and the Federal Bureau of Investigation.
DoD funding for military activities support a broad range of activities. The largest category, operation and maintenance, cost $332 billion in FY2024. It covers the cost of military operations such as training and planning, maintenance of equipment, and most of the military healthcare system (separate from outlays made by the Department of Veterans Affairs). The second largest category, military personnel, supports pay and retirement benefits for service members and cost $192 billion in FY2024.
Several smaller categories accounted for the rest of DoD spending. Procurement of weapons and systems cost $152 billion in FY2024 and $138 billion was spent on research and development of weapons and equipment. The military also spent more than $12 billion on the construction and management of military facilities and $2 billion on family housing.
How Has National Defense Spending Changed Over Time?
The composition of DoD spending has varied over time. Operation and maintenance accounted for 38 percent of military spending in 2024, which is up from 28 percent of all military spending in 1974. Although the Vietnam War had just ended and operational costs were significant, they were still small compared to other spending categories. For example, a much larger share of military spending was devoted to military personnel and procuring weapons and systems at that time.
Two large categories of spending have a close relationship with the defense budget, though they technically fall outside of it. The first is veterans benefits and services, on which the federal government spent $326 billion in 2024. Those commitments arise in part from past military decisions. The second is international affairs, to which the federal government devoted $78 billion in 2024 for discretionary spending on activities such as humanitarian assistance and international development. That spending influences political and economic developments in other countries and can therefore affect future decisions on military involvement and defense spending. Those categories, and their relationship to national defense, highlight the federal government’s significant budgetary commitment in this area.
National Defense Spending Remains a Top Priority of the Federal Government
The national defense budget funds a wide range of activities and represents a significant share of overall federal spending. Indeed, the United States spends more than any other advanced economy in this area, not only in raw dollars, but also as a share of the economy. While the appropriate level of defense funding is part of an ongoing debate, one thing is clear — national defense spending is currently one of the top priorities of the U.S. federal government.
Further Reading
Infographic: The Facts About U.S. Defense Spending
National security is both a vital priority and a significant part of the federal budget.
What Is Budget Reconciliation?
The reconciliation process avoids the potential need to gather 60 votes to end debate and, therefore, allows the Senate to adopt legislation with a simple majority.
Spending on Veterans in the Budget
This piece examines spending on veterans within the budget and outlines the factors that have pushed it higher in recent years.