Defense Primer: The NDAA Process

Defense Primer: The NDAA Process

Defense Primer: The NDAA Process

Updated December 4, 2025 (IF10515)

The National Defense Authorization Act (NDAA) provides authorization of appropriations for the Department of Defense (DOD), nuclear weapons programs of the Department of Energy, and other defense-related activities. In addition to serving as an authorization of appropriations, the NDAA establishes defense policies and restrictions, and addresses organizational administrative matters related to the DOD. Unlike an appropriations bill, the NDAA does not provide budget authority for government activities. Nevertheless, historically it has provided a fairly reliable indicator of congressional sentiment on subsequent appropriations for particular programs.

FY2025 was the 64th consecutive fiscal year for which a defense authorization was enacted. This regular enactment of legislation for more than six decades depends upon adherence to process and consistency in procedures, schedules, and protocols.

Committees of Jurisdiction

The House Committee on Armed Services (also known as the House Armed Services Committee, or HASC) and the Senate Committee on Armed Services (also known as the Senate Armed Services Committee, or SASC) have jurisdiction over all bills, resolutions, and other matters relating to the common defense under the Rules of the House and Senate. Referred to as the authorizers or the authorizing committees, the HASC and the SASC each has subcommittees that are assigned jurisdictional responsibilities by the full committee. In the 119th Congress, the HASC established seven subcommittees:

Cyber, Information Technologies, and Innovation;

Intelligence and Special Operations;

Military Personnel;

Readiness;

Seapower and Projection Forces;

Strategic Forces; and

Tactical Air and Land Forces.

The SASC established seven subcommittees:

Airland;

Cybersecurity;

Emerging Threats and Capabilities;

Personnel;

Readiness and Management Support;

Seapower; and

Strategic Forces.

The NDAA Timeline

The NDAA process begins on or about the first Monday in February of each year, with the submission of the President's budget request to Congress, though the submission is sometimes delayed. The Administration often submits policy proposals (i.e., requests for legislation) to the committees of jurisdiction in conjunction with the budget request. DOD periodically submits packages of legislative proposals for inclusion in the NDAA.

The authorizing committees begin their work on the NDAA in parallel with one another. Both committees conduct a series of hearings on the budget request and related matters, which typically lead to the drafting and markup of separate bills in the House and the Senate.

Hearings

Upon receipt of the President's budget request, the HASC and the SASC begin a series of posture hearings in which the senior civilian and military leadership of the DOD, the military services, and certain defense agencies are invited to testify before the committees on the budget request. The subcommittees also conduct related hearings, with a focus on issues specific to that subcommittee's jurisdiction. For example, the SASC may hold a hearing with the Secretary and Chief of Staff of the Army on that year's budget request for the Army, and the Airland Subcommittee might follow with a hearing specifically looking at the Army's ground vehicle procurement programs.

Markup

In a typical year, the committees will have reviewed the President's budget request and associated policy proposals and prepared authorizing legislation for markup in committee by late April or May. These meetings are called markups, because committee members mark up the legislation by considering, debating, and voting on amendments to the authorizing bill.

Subcommittee Markup

In current practice, both the HASC and the SASC begin the markup process in subcommittee, with each of the subcommittees considering the subcommittee chair's mark (or subcommittee print), a draft legislative proposal with funding recommendations for matters in the bill under that subcommittee's jurisdiction. At completion of markup, each subcommittee votes to report the proposal, as amended, to the full committee.

Full Committee Markup

Once the subcommittees have all finalized their markups, the full committee convenes to consider, debate, and vote on amendments to each of the subcommittee marks. During full committee markup, the full committee chairman's mark (or chair's mark), which contains legislation and funding recommendations for matters that are not assigned to a specific subcommittee, is also considered, debated, and voted on. The chair's mark addresses a variety of cross-cutting issues such as general defense policy, matters related to the organization and management of the DOD, acquisition and industrial base policy, and matters related to foreign nations and overseas contingency operations.

Common HASC Committee Practices

The enrolled version of the FY2025 NDAA (P.L. 118-159) included 794 pages of bill text and discretionary authorizations totaling $883.7 billion. To shepherd a bill of this magnitude through the legislative process, the HASC has adopted several common practices in drafting and marking up the NDAA.

For example, in 2024, prior to committee consideration of the legislation, the committee promulgated guidance for House Members to submit Community Project Funding requests for inclusion in the bill. During markup, the committee typically also requires that committee members provide, before offering any amendment that involves the jurisdiction of other House committees, a letter from the respective committee chair indicating a waiver of the right of referral. This requirement is also imposed on legislation in the underlying mark. Doing so avoids potential delays that could result from a sequential referral of the bill to other committees. In addition, the committee's markup practice has often required that amendments that would increase spending for an item identify a suitable offset.

Common SASC Committee Practices

Under Senate rules, committees and their subcommittees may vote to hold closed meetings for specific reasons (e.g., to avoid disclosing certain national security information). The SASC full committee markups (and most subcommittee markups) are generally conducted in closed session. In addition, the SASC proposal is typically reported to the Senate as an original bill (i.e., its text has not been previously formally introduced).

Floor Consideration

Once reported favorably out of committee, the NDAA may be scheduled for floor consideration. In the House, current practice is to consider the bill under the provisions of a special rule that structures the conditions of debate and possible floor amendments to the bill. The rule has sometimes made in order (i.e., allowed to be offered) hundreds of amendments (many of which are offered and agreed to en bloc). After being considered, debated, and amended in the House, the House-passed version of the NDAA is sent to the Senate and typically either referred to SASC or placed on the Senate calendar.

In the Senate, after SASC has reported its proposal, any floor debate and amendment consideration is typically structured pursuant to multiple unanimous consent agreements. The Senate has sometimes considered more than 100 floor amendments. However, one or more cloture processes (by which three-fifths of the Senate, typically 60 Senators, votes to limit consideration) may be necessary to reach a final vote on certain amendments, and on the bill itself.

If the Senate passes its own bill first, it is sent to the House; often, instead, the Senate takes up the House bill it has received and considers amendments to it (including the proposal reported by SASC).

Conference

The Constitution requires that the House and Senate approve the same bill in precisely the same form before it is presented to the President. To this end, each chamber must pass its own version of the same measure and then attempt to reach agreement with the other chamber about its provisions. An agreement may be reached by the exchange of alternatives between the chambers. Alternatively, the House and Senate can each agree to create a conference committee to propose a package settlement of the competing proposals.

A conference committee is traditionally used to resolve differences between the chambers on the NDAA. Conferees are House and Senate members, drawn mainly from the HASC and SASC, who are expected to resolve disagreements between the House and Senate positions and provide an agreement in the form of a conference report. Conferees may also be appointed from other committees with jurisdiction over components of the bill; each chamber may limit the provisions on which its conferees may negotiate. The conference committee will typically begin its work as soon as possible following passage of a proposal in each chamber. Completion of the conference report is not on a specified timeline, but many of the authorities provided by the NDAA expire at the end of the fiscal year. Therefore, considerable effort is put toward completing the NDAA conference prior to October 1 of each year.

Once reported by the conference committee, a conference report is subject to debate during floor consideration, but is not amendable. (In the Senate, reaching a vote on the conference report may require three-fifths of the Senate to invoke cloture.) If the House and Senate each agree to the conference report, the NDAA is enrolled for presentation to the President.

CRS Products

CRS In Focus IF10516, Defense Primer: Navigating the NDAA

CRS In Focus IF10514, Defense Primer: Defense Appropriations Process

CRS Report R42843, Introduction to the Legislative Process in the U.S. Congress

CRS Report R46497, Authorizations and the Appropriations Process

CRS Infographic IG10005, From Bill to Law: Stages of the Legislative Process

Note: For questions on the legislative process, congressional clients may contact Valerie Heitshusen; for questions on the NDAA, congressional clients may contact Daniel M. Gettinger. Acknowledgment: This primer was originally coauthored by Lynn M. Williams, former CRS Specialist in Defense Readiness and Infrastructure.