GovernmentDefense

What does the Department of Defense do?

Data updated January 23, 2025

The Department of Defense is an agency of the executive branch tasked with maintaining and overseeing the military forces of the United States. Its primary functions include overseeing the Army, Navy, Air Force, Marine Corps, and Space Force; creating military policies; and managing the defense budget. It was established in 1947.

Other names and abbreviations for the Department of Defense:

  • DOD
In FY 2024,

$925B

was spent by the Dept. of Defense
In FY 2024,

13.6%

of federal spending was by the Dept. of Defense
The Department of Defense spent $925 billion in fiscal year (FY) 2024. This was 13.6% of the $6.8 trillion in overall federal spending. The department ranked fourth among federal agencies in total spending.

The Department of Defense accounted for 13.6% of all federal spending in FY 2024.

10 government agencies accounted for 97.0% of federal spending in FY 2024

Federal spending may shift over time due to population growth, changes in policy and programs, and emerging problems to address. Since FY 1980, overall federal spending has risen 193.7%, while Department of Defense spending has increased 62.7%.
The department’s spending grew less than overall spending, which means that the department’s share of the federal budget increased. In FY 2024, the Department of Defense accounted for 13.6% of all federal spending, 11.0 percentage points lower than in FY 1980. In the last 10 years, that share has decreased 4.8 points.
Major legislation, internal or global economic conditions, and acute events like the COVID-19 pandemic can affect spending year to year. For example, the federal budget fluctuated during the pandemic, rising from $5.3 trillion (in 2023 dollars) in 2019 to $7.7 trillion in 2020 and $7.8 trillion in 2021.

The Department of Defense’s share of federal spending in FY 2024 was lower than FY 1980.

Percentage of federal budget dedicated to DOD, FYs 1980–2024

Most federal spending can be categorized as direct or indirect. Direct spending refers to money the federal government spends on budget items such as federal programs, employee salaries, and debt interest. Indirect spending refers to federal transfers to state and local governments.
In FY 2024, the Department of Defense transferred less than 0.05% of its total spending to states and local governments.
The chart below outlines all DOD spending.

How did the Department of Defense spend its budget in 2024?

Federal government spending isolated to DOD, FY 2024

Who leads the Department of Defense?

DOD is led by the secretary of Defense, who is nominated by the president, confirmed by the Senate, and then sworn into office. The defense secretary is one of the 15 cabinet members serving at the president's discretion. This appointed position typically ends when the appointee resigns, is replaced, or when a new president takes office and appoints their own cabinet. Some cabinet members serve temporarily during transitions between administrations.


In addition to the secretary and deputy secretary of defense, DOD leadership includes the chairman of the Joint Chiefs of Staff, the nation's highest-ranking military officer and foremost military advisor.


The DOD is housed in the Pentagon.

Methodology

USAFacts standardizes data, in areas such as time and demographics, to make it easier to understand and compare.

Page sources

USAFacts endeavors to share the most up-to-date information available. We sourced the data on this page directly from government agencies; however, the intervals at which agencies publish updated data vary.

  • Office of Management and Budget and US Department of the Treasury

    Budget of the US Government and Monthly Treasury Statement

    Office of Management and Budget and US Department of the Treasury logo