FY2025 Budget Request: Department of Defense-Military (Subfunction 051)

On March 11, 2024, the Biden Administration released an FY2025 budget requesting a total of $7.5 trillion in budget authority. Of this total, $850 billion (11.35%) covered discretionary spending for Department of Defense (DOD) military programs (Budget Subfunction 051) and $22 billion covered mandatory spending for DOD military programs. This CRS Insight summarizes requested discretionary spending, end strength, and acquisition efforts for this budget subfunction (see Table 1).

DOD's discretionary budget request—also called the base budget—presents the Administration's view of the funding required to implement the National Defense Strategy by staffing, training, and equipping the armed forces under acceptable risk within spending limits established by the Fiscal Responsibility Act (P.L. 118-5). The base budget request excludes DOD unfunded priorities and supplemental funding requests.

Congress annually determines whether to authorize and/or fund individual line items in the base budget at amounts greater than, less than, or equal to the Administration's requested figure.

How does Congress utilize DOD's budget request?

Congress assesses the Administration's budget request through committee hearings, markups, floor debates, and votes to determine which DOD military programs should be authorized and funded at particular dollar amounts. The House and Senate Armed Services Committees (HASC and SASC) generate versions of a National Defense Authorization Act (NDAA) to authorize particular programs at particular dollar amounts. The House and Senate Appropriations Committees (HAC and SAC) generate versions of a Department of Defense Appropriations Act and Military Construction and Veterans Affairs Appropriations Act to appropriate public funds toward authorized DOD Military programs.

Accessing authoritative data sources to evaluate DOD's budget request

Congressional staff seeking authoritative DOD budget request information may consult several authoritative sources. The Office of Management and Budget's website for the President's Budget situates DOD funding alongside other agencies through a budget appendix and historical tables. Each federal agency is also required by law to make its unclassified budget request documents available on an agency website. DOD provides summary budget documents on its Chief Financial Officer (CFO) website, including an FY2025 defense budget overview, an overview of acquisition program costs, and a set of funding tables known as the Green Book containing DOD-specific historical data and future cost estimates. The DOD CFO website also contains spreadsheets summarizing requested dollar amounts for each appropriation account at the line-item level, called "Dash-Ones" because of their document titles. Finally, each armed service provides detailed budget justifications on its own agency website, including narrative descriptions connecting programs to defined mission areas. For ease of access, the DOD CFO's budget website provides links to these agency websites.

Congressional staff seeking authoritative information from these data sources may find discrepancies among dollar values for a given appropriation account due to variation in OMB and DOD methodologies for constructing funding tables. Table 1 provides summary information based upon DOD's Defense Budget Overview, cross-referenced to OMB's DOD Budget Appendix. Since Congress had not enacted FY2024 appropriations when DOD submitted its FY2025 budget request to Congress, Table 1 takes FY2024 enacted values from explanatory statements accompanying the Consolidated Appropriations Act, 2024 (P.L. 118-42) and Further Consolidated Appropriations Act, 2024 (P.L. 118-47).

Figure 1 displays FY2025 requested amounts by appropriation, as a percentage of the $850 billion total.

Figure 1. Department of Defense FY2025 Budget Request (Base) By major appropriation title as percentage of total base budget request

Source: CRS analysis of Under Secretary of Defense (Comptroller)/Chief Financial Officer, Defense Budget Overview: United States Department of Defense Fiscal Year 2025 Budget Request, March 2024, p. A-7. Note: "Other" includes Revolving and Management Funds and Offsetting Receipts.

Figure 2 provides historical context, displaying congressional appropriations of DOD budget authority from FY1948 through the FY2025-FY2029 Future Years Defense Program (FYDP).

Figure 2. Department of Defense Budget Authority by Public Law Title, FY1948-FY2029 In billions of constant FY2025 dollars

Source: CRS analysis of Department of Defense, National Defense Budget Estimates for FY2025, April 2024, Table 6-8. Notes: FY2025 through FY2029 values reflect requested or projected amounts. Military personnel amounts include "Retired pay, defense." "Other" includes Revolving and Management Funds; and Trust, Receipts, and Other. DOD's April FY2024 Green Book does not incorporate FY2024 enacted funding. As a result, FY2024 values reflect requested, not enacted values. Figures exclude War Outyear Placeholder.

DOD FY2025 Requested End Strength (Troop Levels)

End strength refers to the total authorized quantity of servicemembers on hand at the end of a fiscal year. DOD requested Congress to authorize 1.28 million active duty servicemembers and 0.77 million reserve servicemembers for FY2025. Table 2 provides a breakout of these requests by service component.

Figure 3. Department of Defense Active Duty End Strength by Service, FY2000-FY2025

Source: CRS analysis of DOD appropriations acts, DOD budget requests, and Office of the Assistant Secretary of Defense for Manpower and Reserve Affairs' Defense Manpower Profile Reports. Notes: FY2000-FY2023 = actual end strength. FY2024 values = enacted (authorized). FY2025 values = requested.

FY2025 Combat Force Structure Overview

DOD's military personnel requirements are closely associated with the organization and structure of each service's combat forces. Table 3 reports the department's FY2025 requested combat force structure.

The combat force structure overview provides a net quantity for aircraft inventory and battle force ships. The net quantity includes new acquisitions and retirement or divestment of aircraft and ships. The FY2024 NDAA (P.L. 118-31, Section 151) required DOD to submit a budget exhibit "that includes the savings built into the budget for force structure retirements and divestments submitted with the President's Budget request." Table 4 provides DOD's reported FY2025 aircraft and ship retirements/divestments and associated summary cost savings.

Figure 4 reports DOD's FY2025 total requested investments in the RDT&E and Procurement appropriations, sorted by weapon system type and mission area.

Figure 4. Department of Defense Combined RDT&E and Procurement Investments, FY2025 Requested In billions of nominal dollars

Source: Under Secretary of Defense (Comptroller)/Chief Financial Officer, Program Acquisition Cost by Weapon System: United States Department of Defense Fiscal Year 2025 Budget Request, March 2024, p. 1. Notes: Total covers all DOD RDT&E and Procurement budget requests. Categorization is selected by DOD "to simplify display of the various weapon systems being developed and procured in FY2025." Science & Technology includes RDT&E budget activities 1-3. C4I refers to command, control, communications, computers, and intelligence.

Table 5 provides more detail on selected weapon system investments in each mission area (excluding "Science & Technology" and "Mission Support Activities.") Hyperlinks in the table's left column provide one-page narrative descriptions of each program, along with links in the center column to selected CRS products contextualizing the program.