U.S. Debt Interest Hits $1.1 Trillion as Yields Top 5%

Interest payments on the U.S. national debt reached $1.1 trillion in fiscal 2026, consuming 3.4% of gross domestic product and surpassing both defense spending and Medicare for the first time in modern history. The milestone, recorded as the federal government closed its books on Wednesday, signals that compounding borrowing costs have overtaken traditional budget drivers as the primary threat to American fiscal stability.

The $2 trillion deficit recorded for the fiscal year ending Sept. 30 left publicly held debt at $32.3 trillion, or roughly 100% of GDP. Unlike previous eras when Washington ran large deficits primarily through new program spending or wartime outlays, the current deterioration is being driven by the mathematical mechanics of refinancing existing obligations at substantially higher rates.

Borrowing costs have accelerated far beyond official projections. The benchmark 10-year Treasury yield recently touched 5.27%, a level the Congressional Budget Office did not anticipate reaching until well into the next decade. CBO baseline models assumed 10-year yields would average 4.3% between 2028 and 2031, rising only marginally to 4.4% through 2036. Because the Treasury must constantly roll over maturing securities, every percentage point of unexpected yield translates directly into hundreds of billions of dollars in unbudgeted expenses. The Committee for a Responsible Federal Budget estimates that sustained yields running just 1 percentage point above CBO forecasts will add approximately $3.5 trillion to the national debt over the next decade.

Scope Ratings, which affirmed the U.S. sovereign grade at AA- on Friday with a stable outlook, calculated that general government debt will approach 160% of GDP by 2036 without significant policy intervention. The European agency noted that primary deficits—borrowing required to fund operations before interest costs are factored in—are expected to hold relatively steady near 3.5% of GDP. The entire trajectory of fiscal deterioration is therefore concentrated in debt servicing.

Washington’s response to rising long-term rates has introduced a distinct set of vulnerabilities. Treasury Secretary Scott Bessent has expanded a strategy initiated under the Biden administration, aggressively shifting the government’s borrowing profile toward short-term maturities. Through targeted buyback operations designed to retire longer-dated bonds using proceeds from newly issued notes, the Treasury aims to reduce immediate interest expenses. While this lowers current carrying costs, it forces the government to refinance its obligations much more frequently. When yields spike, as they have in recent months, rolling over a heavier concentration of short-term paper becomes significantly more expensive.

This maturity shift coincides with a structural change in who holds U.S. debt. Foreign central banks, historically the most predictable and stable buyers of Treasuries, have reduced their footprint. Price-sensitive hedge funds operating basis trades and other leveraged strategies now account for a larger share of activity in the $32 trillion market. These investors react rapidly to rate movements and liquidity conditions, amplifying volatility during periods of stress.

Fiscal 2027, which began Thursday, carries an immediate structural complication: the statutory debt limit. The current ceiling stands at $41.1 trillion, a threshold Scope expects the government to reach by early 2027. Once breached, the Treasury Department relies on accounting maneuvers known as extraordinary measures to continue funding operations without issuing net new debt. These tools typically buy Congress several months of runway, but the upcoming midterm election cycle raises the probability of prolonged partisan negotiations over raising or suspending the limit.

Revenue assumptions underlying current forecasts also face downward pressure. CRFB warned that tariff collections, which the administration projected would offset some borrowing needs, are tracking lower than anticipated. Combined with the surge in interest outlays, actual deficits could exceed CBO models by a wide margin.

Despite these pressures, major credit raters maintain that the U.S. retains fundamental advantages unavailable to any other sovereign borrower. The dollar remains the dominant global reserve currency, the Federal Reserve operates independently, and U.S. capital markets offer unmatched depth and liquidity. Fitch and S&P Global Ratings currently assign the U.S. an AA+ grade, while Moody’s places it one notch higher at Aaa, though all three agencies have either downgraded or assigned negative outlooks to the U.S. in recent years amid recurring fiscal disputes.

CRFB released its final fiscal 2026 accounting data on Wednesday, confirming the $1.1 trillion interest figure as the second-largest line item in the federal budget.