U.S. National Debt: From Persistent Deficits to a Fiscal Sustainability Challenge

Introduction

The U.S. national debt is no longer simply a legacy of wars, recessions or the extraordinary spending of the pandemic. It has increasingly become a structural fiscal challenge. The federal government is spending considerably more than it collects in revenues, requiring persistent Treasury borrowing. At the same time, an aging population is increasing spending on Social Security and Medicare, while rising healthcare costs are adding further pressure. The consequence is a feedback loop: deficits increase borrowing, borrowing increases debt, and a larger debt stock creates larger interest payments. Those interest payments then become part of future deficits.

The Congressional Budget Office (CBO) projects that the federal deficit will reach $1.9 trillion in 2026, while debt held by the public reaches 101% of GDP. Under current-law assumptions, debt rises to 120% of GDP by 2036 and 175% by 2056.

The central problem: spending, revenue and interest

The fundamental fiscal equation is simple: when government spending exceeds revenue, the difference must be financed through borrowing. In 2026, CBO projects federal outlays of $7.4 trillion against revenues of $5.6 trillion, producing a deficit of approximately $1.9 trillion.

What makes today's situation different from an ordinary cyclical deficit is its persistence. CBO projects the deficit to reach $3.1 trillion, or 6.7% of GDP, by 2036, even though the economy is not assumed to remain in recession. Revenues remain around 17–18% of GDP, while spending rises to 24.4% of GDP.

The composition of spending is crucial. Social Security, Medicare and interest costs are growing faster than the economy, while discretionary spending declines as a share of GDP. The result is that fiscal pressure increasingly comes from structural commitments rather than one-off government programs.

1 — The Long-Term Debt Trajectory

The first dataset establishes the scale of the problem. CBO projects federal debt held by the public to rise from 101% of GDP in 2026 to 120% in 2036. By 2056, the ratio reaches 175% of GDP under current-law assumptions.

This is significant because debt is already at historically high levels. CBO notes that debt held by the public surpasses its previous postwar peak of about 106% of GDP during the coming decade. The important point is that debt continues increasing even after the extraordinary pandemic period has ended.

The reason is persistent deficits. CBO projects a $1.9 trillion deficit in 2026, increasing to $3.1 trillion in 2036. Over the 2027–2036 period, cumulative deficits are projected to total roughly $24.4 trillion.

The chart therefore tells a simple story: the U.S. is not merely carrying a large debt balance; it is continuing to add substantial new debt every year.

2 — Where the Federal Money Goes

The second dataset explains why reducing the deficit is difficult. CBO projects $7.4 trillion of federal outlays in 2026, compared with $5.6 trillion of revenues. Outlays are projected to reach $11.4 trillion by 2036.

Federal spending can broadly be divided into mandatory programs, discretionary programs and net interest. Mandatory spending includes Social Security, Medicare and Medicaid and is largely determined by eligibility rules and benefit formulas. Discretionary spending includes defense and numerous domestic programs. Net interest represents the cost of servicing debt held by the public.

The composition is changing. CBO projects outlays to rise from 23.3% of GDP in 2026 to 24.4% in 2036, driven primarily by Social Security, Medicare and increasing interest costs. At the same time, discretionary spending declines as a share of GDP.

This means the fiscal problem cannot be understood simply as excessive discretionary spending. Increasingly, the pressure comes from programs whose costs are tied to demographics, healthcare and the accumulated debt itself.

3 — Healthcare and Demographics

Healthcare is perhaps the most important long-term structural pressure. The U.S. population aged 65 and older is now almost three times its size 50 years ago, and CBO expects that population to increase by about 15% over the coming decade. More elderly Americans means more people receiving Social Security and Medicare.

But demographics are only half the story. Healthcare costs per beneficiary are also increasing. CBO estimates that during 2026–2036, growth in the number of beneficiaries increases Medicare spending by about 20%, while rising costs per beneficiary add another major source of spending growth.

Major federal health programs therefore become an increasingly large budget item. In CBO's long-term analysis, major health-program spending rises substantially as a share of GDP over the coming decades, with Medicare accounting for most of the increase.

The fiscal chain is straightforward:

Aging population → more beneficiaries → higher Medicare spending → larger federal outlays → larger deficits.

Healthcare is therefore not the sole cause of U.S. debt, but it is one of its most important long-term structural drivers.

4 — Treasury Borrowing and Interest Costs

The fourth dataset explains why yesterday's borrowing becomes tomorrow's spending problem. Every persistent deficit requires Treasury financing. As the debt stock grows, the government must pay interest to holders of Treasury securities.

CBO projects net interest outlays to rise from approximately $1.0 trillion in 2026 to $2.1 trillion in 2036. As a share of GDP, interest costs rise from 3.3% to 4.6%.

This is particularly important because interest is different from many other forms of government spending. It does not directly purchase healthcare, infrastructure, education or defense. It represents the financial cost of previously accumulated borrowing.

By 2036, CBO projects net interest to be almost as large as total federal discretionary spending.

The mechanism creates a potentially powerful feedback loop:

Deficit → Treasury borrowing → higher debt → higher interest payments → larger future deficit → more borrowing.

Thus, rising interest costs can gradually reduce the government's fiscal flexibility. Money devoted to servicing old debt cannot simultaneously be used for new priorities without additional borrowing or higher revenues.

 5 — Fiscal Sustainability

The final dataset brings the entire story together. Debt sustainability depends not only on the size of debt but on the relationship between economic growth, primary deficits, interest rates and revenues.

The primary deficit excludes interest payments. CBO projects the primary deficit at 2.6% of GDP in 2026, improving slightly to 2.1% in 2036. Yet the total deficit still rises from 5.8% to 6.7% of GDP, because interest costs increase from 3.3% to 4.6% of GDP.

This distinction is crucial. Even if the government improves its non-interest budget position, the accumulated debt can continue generating larger interest bills.

CBO's long-term current-law projection places debt held by the public at 175% of GDP in 2056. Net interest also reaches a very high level as a share of GDP.

The solution is therefore not one-dimensional. Stabilizing debt would require some combination of stronger economic growth, higher revenues, lower primary deficits and/or lower interest costs.

Conclusion

The U.S. debt challenge is ultimately a problem of compounding fiscal pressures. Persistent deficits create borrowing; borrowing increases the debt stock; the larger debt stock produces higher interest payments; and those interest payments become an additional source of future deficits. At the same time, an aging population and rising healthcare costs are increasing the government's largest long-term spending commitments.

The numbers are significant: CBO projects debt held by the public to rise from 101% of GDP in 2026 to 120% in 2036 and 175% in 2056, assuming current laws generally remain unchanged.

But 175% is not destiny. It is a baseline scenario, not a prediction. Future tax policy, spending decisions, economic growth, interest rates and demographic developments can alter the path.

The central message is therefore simple:

America's debt problem is not just the size of today's debt. It is the growing cost of maintaining a fiscal system in which spending persistently exceeds revenue.

 

U.S. Tariffs: From Trade Barriers to Higher Prices—Who Really Pays?

Introduction

U.S. tariffs have moved from being a trade-policy instrument to a major macroeconomic issue. The central debate is no longer simply whether tariffs reduce imports or protect domestic industries. It is whether the costs ultimately fall on foreign exporters, American businesses, retailers, or consumers. The evidence from the recent tariff cycle suggests the answer is more complicated: the burden is shared across the supply chain, while consumers bear part of it through higher prices and reduced purchasing power.

The scale of U.S. trade makes this important. In 2025, U.S. goods imports reached about $3.44 trillion, while the goods deficit rose to $1.24 trillion. At the same time, the composition of imports changed sharply: the U.S. goods deficit with China fell to $202.1 billion, while deficits with Vietnam and Taiwan increased substantially.

The tariff transmission mechanism

A tariff is formally paid by the U.S. importer at the border, not directly by the foreign government. But the economic burden can move through several stages. The importer may absorb part of the additional cost, negotiate lower prices from suppliers, or pass the increase to manufacturers and distributors. Producers may then absorb some cost through lower margins or pass it forward. Retailers face the same decision before the final price reaches consumers.

This means a 10% tariff does not necessarily produce a 10% increase in the retail price. The final effect depends on competition, supplier alternatives, exchange rates, margins, inventories and consumer demand. New York Fed research on the 2025 tariffs estimates that about 26% of the tariff increase passed through to consumer prices, with direct effects appearing quickly and indirect supply-chain effects taking roughly nine to twelve months.

 1 — U.S. trade with major partners

The first signal is the changing geography of U.S. trade. In 2025, the largest U.S. goods deficits included China at $202.1 billion, Mexico at $196.9 billion, Vietnam at $178.2 billion and Taiwan at $146.8 billion. The China deficit declined by $93.4 billion from 2024, while the Vietnam deficit increased by $54.7 billion and Taiwan's by $73.0 billion.

Chart 1 — U.S. Trade With Top Partners, 2018–2026

Source: U.S. Census Bureau / BEA.

The data illustrate an important limitation of tariffs: reducing imports from one country does not automatically eliminate the underlying U.S. demand for imported goods. Supply chains can be reorganized toward alternative countries. The growth of Vietnam and Taiwan alongside the decline in China's trade relationship is consistent with this diversification effect, although tariffs are only one of several forces shaping trade flows.

 2 — Commodity and input prices

Tariffs become particularly important when they affect goods that American manufacturers use as inputs. Steel, aluminum and copper are examples. A tariff on these materials can increase costs not only for imported metal but also for U.S. companies purchasing metal domestically, because domestic producers may face less competition from imports.

Chart 2 — Steel, Aluminum, Copper and Other Input Prices, 2018–2026
Source: U.S. Bureau of Labor Statistics PPI.

The distinction between tariff effects and general commodity inflation is essential. Commodity prices also respond to energy markets, supply disruptions, construction demand, inventories and global economic conditions. The pandemic demonstrated this dramatically. Therefore, a rise in steel or copper prices cannot automatically be attributed to tariffs. The strongest evidence comes when price movements coincide with tariff changes and are concentrated in tariff-exposed products.

 3 — Industries affected

The impact becomes clearer when commodity inputs are connected to industries. Automobiles use steel, aluminum and imported components. Electronics depend on international semiconductor and component supply chains. Appliances use metals, motors and electronic components. Construction relies on steel, aluminum, lumber and machinery. Furniture, apparel and footwear have significant exposure to imported finished products.

Chart 3 — Industries Ranked by Tariff Exposure
Source: U.S. trade and Federal Reserve/USITC research.

The earlier Section 232 steel and aluminum experience demonstrates the trade-off. U.S. International Trade Commission research found that steel and aluminum tariffs raised domestic metal prices and production, but downstream industries using those metals experienced negative production effects.

The lesson is straightforward: protecting an upstream industry can simultaneously raise costs for downstream industries.

 4 — Retail prices and inflation

The consumer impact is visible, but it is uneven. U.S. CPI inflation was 3.4% year over year in July 2026, while the PCE price index increased 3.7% and core PCE increased 3.3%.

Chart 4 — Tariff-Exposed Consumer Prices and Inflation
Source: BLS CPI; BEA PCE.

Not every increase in inflation should be labelled a tariff effect. Food, energy, housing, wages and services have their own price dynamics. The tariff effect is more visible in exposed goods. Federal Reserve research identifies appliances, electronics, clothing, footwear and other imported consumer categories as particularly sensitive to tariff exposure.

The important conclusion is therefore not that tariffs caused all inflation, but that tariffs added an additional price pressure to selected goods and supply chains.

 5 — Tariff-to-consumer price pass-through

The final question is who absorbs the cost. Federal Reserve research using household transaction data estimates retail price pass-through of roughly 15% using realized tariff rates and about 20% using a broader tariff-exposure measure. At the same time, spending on affected goods fell approximately three times as much as prices rose. Quantity reductions were concentrated in non-essential goods.

Chart 5 — Tariff → Importer → Producer → Retailer → Consumer

This shows why the economic effect extends beyond the price tag. A retailer may absorb part of a tariff through lower margins. A manufacturer may substitute suppliers. A consumer may switch brands, buy a cheaper product or postpone the purchase. Thus, the tariff burden is distributed across margins, prices and quantities rather than appearing entirely as a higher retail price.

Conclusion

U.S. tariffs are therefore much more than a tax at the border. They can reshape trade patterns, increase the cost of industrial inputs, alter business decisions and eventually influence consumer prices and spending. The evidence from the recent tariff cycle shows that the pass-through to consumers is partial, uneven and delayed, rather than one-for-one. The biggest economic question is consequently not simply whether tariffs reduce imports. It is whether the gains to protected industries outweigh the costs imposed on downstream businesses, retailers and households. In a highly interconnected economy, the answer depends on the entire supply chain—not just the customs border.