Defense Budget Dynamics: How Pentagon Spending Drives the Sector

Introduction

The US defense budget is the single most important demand driver for the aerospace and defense value chain. At $850 billion in fiscal year 2025, with FY2026 proposals from the Senate Armed Services Committee pushing toward $925 billion, Pentagon spending funds the weapons systems, platforms, and services that generate revenue for the Big Five primes and thousands of tier 1-3 suppliers. Unlike the capex-driven demand that makes other industrial sub-sectors cyclical, defense spending follows its own political and geopolitical cycle, providing a level of demand visibility that is unmatched elsewhere in industrials.

For A&D investment bankers, understanding the defense budget process, spending trajectory, and allocation priorities is foundational. Budget analysis informs how you value defense companies, how you position sell-side mandates, and how you advise PE sponsors on the demand outlook for potential acquisitions. In interviews for A&D-focused roles, demonstrating familiarity with the budget process and current spending trends is expected.

The annual defense budget follows a structured congressional process that takes approximately 18 months from initial planning to enacted law. Understanding each stage helps bankers anticipate where spending is heading and assess the reliability of demand signals.

National Defense Authorization Act (NDAA)

The annual legislation that authorizes funding levels and sets policy for the Department of Defense, nuclear weapons programs (Department of Energy), and other defense activities. The NDAA does not itself provide money (that requires separate appropriations bills), but it establishes the congressional ceiling for defense spending and signals priorities for specific programs, platforms, and capabilities. The NDAA has been enacted annually for over 60 consecutive years, making it one of the most reliable pieces of annual legislation. Defense companies and their bankers analyze the NDAA to understand which programs are growing, shrinking, or being created.

The process follows three major stages:

Stage 1: President's Budget Request (February). Each fiscal year begins with the President submitting a budget request to Congress, typically in early February. This request reflects the Administration's defense priorities and provides the starting point for congressional deliberation. For FY2026, the initial request was approximately $893 billion for national defense.

Stage 2: Authorization (NDAA). The House and Senate Armed Services Committees each develop their version of the NDAA, hold hearings, mark up the legislation, and ultimately produce a conference report that both chambers vote on. The FY2025 NDAA authorized $895.2 billion in total national defense funding. The FY2026 Senate Armed Services Committee advanced a version proposing $925 billion in total authorization, indicating congressional appetite for spending above the President's request.

Stage 3: Appropriation. Authorization sets the ceiling; appropriation provides the actual money. The House and Senate Appropriations Committees produce defense spending bills that allocate funds to specific accounts (procurement, research and development, operations and maintenance, military personnel). When Congress cannot agree on appropriations bills by the start of the fiscal year (October 1), it passes continuing resolutions (CRs) that fund the government at prior-year levels, which delays new program starts and creates uncertainty for defense contractors.

The US defense budget has grown from approximately $580 billion in FY2015 to $850 billion in FY2025, a compound annual growth rate of roughly 4.3%. Several structural forces suggest continued growth through at least the end of the decade.

Geopolitical competition with China and Russia. The Pentagon's strategic focus on great-power competition drives sustained investment in advanced capabilities: hypersonic weapons, space-based assets, cyber warfare, autonomous systems, and next-generation fighter and bomber programs (F-35 production, B-21 Raider, Next Generation Air Dominance). These programs represent decades of future spending commitments.

Munitions replenishment. The drawdown of US and allied munitions stockpiles (through support for Ukraine, Middle East operations, and increased Pacific readiness requirements) has created a multi-year replenishment cycle that benefits missile manufacturers, ammunition producers, and their supply chains. RTX (Patriot, Stinger, Javelin), Lockheed Martin (HIMARS, JASSM), and General Dynamics (artillery shells) are primary beneficiaries.

Modernization of aging platforms. Much of the US military's equipment dates to the Reagan-era buildup of the 1980s and requires replacement. The nuclear triad modernization (new ICBMs, submarines, and bombers simultaneously) is the most expensive modernization program in history, benefiting Northrop Grumman (Sentinel ICBM, B-21), General Dynamics (Columbia-class submarines), and their extensive supplier networks.

Inflation and cost growth. Defense inflation has consistently exceeded general inflation due to the specialized nature of military procurement. Labor costs for cleared workers, specialty materials, and sole-source components all face structural upward pressure. This cost growth mechanically increases the defense budget even at constant real spending levels.

The defense budget is not a single pool of money. It is divided into major appropriation categories, each of which funds different types of defense activity and benefits different types of companies. Understanding these categories helps bankers identify which companies benefit from specific budget trends.

Procurement funds the purchase of weapons systems, vehicles, aircraft, ships, missiles, and ammunition. This is the budget line most directly tied to defense manufacturer revenue. When procurement spending grows, companies producing platforms and major subsystems see direct revenue increases. The FY2025 budget allocated approximately $170 billion to procurement, with significant increases in missile and munitions accounts reflecting the replenishment imperative.

Research, Development, Test, and Evaluation (RDT&E) funds the development of new technologies and the testing of new weapons systems before they enter production. RDT&E spending reached approximately $141 billion in FY2025, reflecting the Pentagon's investment in next-generation capabilities (hypersonics, directed energy, artificial intelligence, autonomous systems). Companies that specialize in R&D and prototyping (Northrop Grumman's advanced technology divisions, DARPA contractors, defense technology startups) benefit most from RDT&E growth.

Operations and Maintenance (O&M) is the largest single category, funding the day-to-day operations of the military: training, equipment maintenance, base operations, and readiness activities. O&M spending exceeded $300 billion in FY2025. This category benefits maintenance, repair, and overhaul (MRO) providers, government IT and services companies (Booz Allen Hamilton, SAIC, Leidos), and logistics support contractors.

Military Personnel funds pay, benefits, and healthcare for active duty and reserve forces. While this category does not directly generate defense contractor revenue, it represents a significant portion of the total budget and competes with procurement and RDT&E for funding share.

The relative growth rates of these categories signal where the demand environment is shifting. A budget that increases procurement and RDT&E faster than O&M and personnel signals an investment-oriented posture that benefits hardware manufacturers. A budget emphasizing O&M and readiness benefits services and sustainment companies. Bankers track these shifts to advise clients on positioning and to identify which program areas will drive the next wave of M&A activity.

While the structural trend supports continued defense budget growth, bankers must also understand the risks that could slow or reverse the trajectory.

Fiscal constraints and debt ceiling dynamics. The US national debt has created periodic political pressure to constrain all federal spending, including defense. The Budget Control Act of 2011 led to sequestration, which imposed automatic defense spending cuts in 2013-2015 and caused real revenue declines for defense contractors. While the current political environment strongly supports defense spending, future fiscal constraints remain a risk that bankers must factor into long-term projections, particularly for LBO models where the hold period may span multiple budget cycles.

Shifting administration priorities. While defense spending enjoys bipartisan support, the degree of support and the allocation priorities shift with administrations. A more isolationist foreign policy posture might constrain the pace of growth, while a more confrontational posture (particularly toward China) could accelerate it. Pentagon spending priorities also shift between administrations: one may emphasize advanced technology (RDT&E), while another may prioritize readiness and force structure (O&M and procurement).

Production capacity constraints. Even with rising budgets, the defense industrial base faces capacity constraints that limit how quickly spending increases translate into revenue. The ammunition and munitions sector, for example, requires new production facilities and skilled workers to meet replenishment demand, and these capacity builds take years. Companies cannot immediately convert higher budget authority into higher revenue if they lack the production capacity to fulfill contracts. This creates a longer revenue ramp for some program areas than the budget authority alone would suggest.

The defense spending story extends well beyond the United States. NATO allies collectively spent over $482 billion on defense in 2024, and spending commitments are accelerating dramatically.

The original NATO benchmark called for allies to spend at least 2% of GDP on defense. As of 2025, all NATO allies are expected to meet or exceed this threshold, compared to only three allies in 2014. European allies and Canada collectively increased defense spending from 1.43% of GDP in 2014 to over 2.02% in 2024, a transformation that represents hundreds of billions of dollars in incremental demand.

More significantly, NATO has adopted a new target of 5% of GDP on defense and security-related spending by 2035, with 3.5% directed to direct defense expenditure. If implemented, this target would push global NATO defense spending from its current combined level toward $2.6 trillion globally by 2026 and well beyond that by 2035. For context, the US currently spends approximately 3.4% of GDP on defense, meaning even the world's largest military spender would need to increase spending significantly to reach the 5% target. Global defense spending is projected to exceed $2.6 trillion in 2026, reflecting the broadest increase in military investment since the end of the Cold War. This global spending acceleration creates opportunities for US defense exporters (Lockheed Martin's F-35 international sales, RTX's Patriot missile system exports) and for European defense companies that are scaling up to meet their own governments' rising demands.

The defense budget creates a level of revenue visibility for defense companies that is exceptional among industrial sub-sectors. This visibility flows from several structural characteristics of defense procurement.

Multi-year procurement authority. Congress authorizes multi-year procurement contracts for major weapons systems, committing to purchase a fixed number of units over 3-5 years. These contracts provide ironclad revenue visibility that reduces forecasting uncertainty to near zero for the covered period. Lockheed Martin's F-35 multi-year procurement contracts, for example, provide revenue visibility extending years into the future.

Program backlogs. Defense companies report funded backlogs (contracts for which money has been appropriated) and total backlogs (including contracts that are authorized but not yet funded). Lockheed Martin's total backlog reached a record $194 billion at year-end 2025, representing approximately 2.5 years of revenue at current run rates. This backlog provides a revenue floor that virtually no other industrial sub-sector can match.

Budget transparency. The defense budget is publicly documented in extraordinary detail. Bankers can access the President's Budget Request, Service-level budget justification books (known as "J-books"), and congressional committee reports to understand exactly how much is being requested for specific programs. This transparency allows A&D bankers to build bottom-up program-level revenue models for defense companies, a level of analytical precision not available in most other industrial sub-sectors.

Funded Backlog vs. Total Backlog

Funded backlog represents the value of contracts for which the government has obligated (set aside) appropriated funds. This is the most reliable measure of near-term revenue visibility because the money is already committed. Total backlog includes funded backlog plus the value of contracts that have been awarded but for which all funding has not yet been obligated (common in multi-year contracts where Congress appropriates money annually). Total backlog provides a longer-term demand signal but carries some risk if future appropriations do not materialize. Bankers typically use funded backlog for near-term revenue modeling and total backlog for strategic positioning arguments.

For bankers covering the A&D sector, defense budget analysis enters the work in multiple contexts.

Sell-side positioning. When advising a defense company on a sale, the banker frames the budget environment as part of the investment thesis. "The FY2026 NDAA proposes $925 billion in total authorization, up from $850 billion in FY2025. The company's core programs (electronic warfare, missile defense, space systems) are aligned with the Pentagon's priority areas, creating multi-year revenue growth visibility that exceeds typical industrial sub-sectors."

Valuation support. Defense companies trade at premium multiples (12-16x EBITDA for primes) partly because their budget-driven revenue visibility reduces earnings uncertainty. Bankers justify these premiums by demonstrating the connection between budget line items and company-specific revenue, showing that the demand is not speculative but rather backed by congressional authorization and appropriation.

PE investment thesis. When advising PE sponsors on defense acquisitions, bankers assess which budget accounts are growing (munitions, cyber, space, autonomous systems) and which are flat or declining (legacy platforms being sunset). A PE firm acquiring a defense supplier wants assurance that the company's programs are aligned with budget growth areas, not tethered to declining programs that will see funding cuts.

Program-level revenue modeling. The most sophisticated A&D bankers build bottom-up revenue models that tie individual program funding lines in the budget to specific revenue streams at the company being analyzed. For a missile manufacturer, this means mapping Congressional appropriation for each missile program (Patriot, JASSM, LRASM, Stinger) to the company's production rates and contract values. This program-level granularity produces revenue forecasts that are far more defensible than top-down approaches based on total budget growth rates, and it allows bankers to identify risks (a specific program facing cuts) and opportunities (a new program entering production) that top-down analysis would miss.

Timing around budget milestones. The annual budget cycle creates predictable information release dates that affect deal activity. The President's Budget Request (February), NDAA markup season (spring/summer), and final appropriation votes (typically December, though often delayed) each provide new data points about defense spending direction. Experienced A&D bankers time sell-side launches and buyer outreach around these milestones, positioning transactions to benefit from positive budget news when possible.