WASHINGTON, Aug 19 - The U.S. federal government's total public debt exceeded $40 trillion for the first time this week, a milestone the Treasury Department recorded in its daily cash and debt balances. The report showed total public debt outstanding at $40.047 trillion as of Tuesday, comprising $32.266 trillion in Treasury securities held by the public and $7.782 trillion in intra-governmental holdings.
The path to this threshold reflects a sharp acceleration in borrowing over the past decade. When President Donald Trump took office in January 2017, total public debt stood at $19.95 trillion. Since then the federal IOU has more than doubled, with roughly one-third of the cumulative increase concentrated in two years of heavy borrowing to finance COVID-19 pandemic responses implemented under both President Trump and President Joe Biden.
Outside those pandemic years, fiscal policy choices across administrations and persistent gaps between revenues and obligations have driven the remainder of the increase. Budget watchdogs have been tracking the approach to the $40 trillion mark for weeks and have issued pointed warnings about the fiscal trajectory unless lawmakers opt to raise revenues, cut spending or pursue a combination of the two.
Market response and investor behavior
Investors have begun to demand higher returns to compensate for the growing supply of longer-dated Treasuries. Yields on 30-year Treasury bonds recently climbed to levels not seen since 2004 and a $25 billion auction of 30-year securities cleared at the highest yield since 2021. The term premium on 10-year Treasuries - the portion of yield attributable to the risk of holding the bond over a decade - rose this week to its highest point in more than a dozen years.
At the same time, demand from foreign holders has waned. Foreign investors, who own nearly one-third of Treasuries, reduced their appetite for U.S. debt over the past year, a trend that leaves a larger share of new issuance to be absorbed by more price-sensitive domestic buyers. John Canavan, lead financial market analyst in the Macroeconomic and Investor Services group at Oxford Economics, warned that the shift toward price-sensitive purchasers can contribute to greater market volatility.
In response to the pressure on long-term yields, U.S. Treasury Secretary Scott Bessent announced an expansion of the Treasury's buyback operations. The Treasury will double the size of buybacks for 10- to 30-year notes to at least $4 billion per operation, a tactical step aimed at reducing upward pressure on long-end yields.
What is driving the increase in debt?
The Treasury pointed to persistent deficits and rising mandatory spending as central drivers. The Treasury last week reported a $432 billion deficit for July, the fourth-largest monthly shortfall on record. That gap was widened by tariff refunds that turned customs receipts negative for a third consecutive month and by growing outlays for Social Security and Medicare benefits.
For the first 10 months of fiscal 2026, the cumulative deficit has already surpassed the total shortfall recorded for the whole of fiscal 2025, with two months remaining in the fiscal year. Such run rates reflect a combination of spending commitments that increase automatically and revenue streams that have not kept pace.
Public debt accumulation during recent administrations has been substantial. Over President Trump's first term the public debt increased by $7.8 trillion, with more than half of that growth concentrated in the pandemic response during his final nine months in office. Since a second inauguration in January 2025, public debt has risen an additional $3.8 trillion, bringing the total increase across his two terms so far to $11.6 trillion. During President Biden's term, public debt grew by $8.4 trillion as well, driven in part by pandemic-related aid but also by large expenditures on infrastructure, clean energy incentives and related priorities.
The non-partisan Committee for a Responsible Federal Budget has estimated that the policy decisions of both administrations have pushed the federal debt path above what would have accumulated under the spending rules in place at the start of each presidency. The Congressional Budget Office has also projected that Trump's second-term legislative package - referred to in the budget analysis as the One Big Beautiful Bill Act - will add $4.7 trillion to the debt trajectory.
Structure of federal spending and rising debt service
The federal budget is largely driven by mandatory programs that operate on automatic trajectories. The United States spends approximately $7 trillion annually, and about 60% of that amount flows to mandatory programs such as Social Security, Medicare, Medicaid and veterans' benefits. These programs typically have built-in growth mechanisms that cause outlays to rise with living costs and eligibility patterns.
Interest payments on the national debt are also climbing. The government currently pays about $1.1 trillion annually in debt service - a cost that expands as borrowing increases and interest rates climb. In the 2025 fiscal-year budget, debt service costs surpassed Pentagon funding for the first time. Over the first 10 months of fiscal 2026, interest expenses have exceeded Medicare outlays and are now the second-largest budget line, trailing only the Social Security pension program.
Policy debates have emphasized different levers to address the imbalance. Administration officials and some lawmakers have advocated for reductions in discretionary spending while acknowledging that discretionary programs make up a small fraction of total federal outlays relative to mandatory programs and interest costs. President Trump has highlighted efforts to cut federal agency jobs through a non-governmental Department of Government Efficiency, but most of the budget's growth has been in entitlement and debt service areas that are less amenable to short-term discretionary trimming.
Voices of concern
"This bleak milestone serves as yet another reminder that it’s past time to confront a fundamental mismatch," Margaret Spellings, CEO of the Bipartisan Policy Center, said as the $40 trillion threshold approached.
"Our federal programs spend much more than the government takes in, and the biggest-ticket items in the federal budget are all running on autopilot," Spellings added. "Federal debt is already raising the cost of living and choking out other spending and investment, threatening our economy and Americans’ long-term prosperity."
Those warnings come as policymakers and market participants weigh whether fiscal adjustments - higher taxes, lower spending or a mix of both - will be pursued and at what scale. For now, the combination of elevated borrowing, shifting investor demand and automatic growth in entitlement spending has pushed the government's balance sheet past a symbolic but consequential line.
Implications and next steps
The Treasury's decision to increase buyback sizes for longer-term paper is a tactical effort to moderate yields, but the fundamental fiscal drivers remain centered on mandatory programs and interest costs. With foreign demand for Treasuries diminished compared with a year ago, more issuance will need to be absorbed by domestic investors whose appetite can be more sensitive to price.
Lawmakers face a constrained set of choices: increase revenue, reduce certain spending streams, or allow deficits and interest costs to continue rising. The mix of those decisions will determine how quickly debt growth could be slowed - or whether the nation will continue on the current trajectory that has taken public debt from under $20 trillion to over $40 trillion in fewer than 10 years.
For markets, the near-term focus will remain on auction demand, yield dynamics at the long end of the curve, and the fiscal decisions Congress and the administration make as the budget outlook evolves.