US government borrowing costs are a growing concern, with the benchmark 10-year Treasury yield averaging 4.3 percent early in 2026 and rising to nearly 4.6 percent by mid-August. The 30-year Treasury yield peaked at 5.34 percent in mid-August, its highest since 2007, before settling around 5.17 percent. This surge in yields, partly attributed to the normal laws of supply and demand for the increasing US debt, has prompted Treasury Secretary Scott Bessent to intervene in an attempt to lower them.
The immense federal debt, exceeding $32 trillion and recently topping $40 trillion, makes the US highly sensitive to interest rate changes. Interest outlays for Washington soared to $970 billion last year, up from $350 billion in 2021, and are projected to consume 19 cents of every tax dollar, up from 11 cents at the turn of the century. The Congressional Budget Office estimates that a mere 0.1 percentage-point increase in the 10-year Treasury yield, sustained over a decade, would hike federal deficits by $379 billion.
The broader economic implications are significant: higher Treasury yields translate into increased borrowing costs for mortgages, car loans, and business investments. This can slow consumption, the largest component of US GDP, and dampen private investment, which constitutes 18 percent of GDP. While higher borrowing costs can lead to some increased tax revenue from interest income (especially from higher-income bondholders and corporate lenders), these positive effects are largely overshadowed by the negative impacts of reduced economic activity and increased government interest payments. The government also faces increased interest deductibility, as borrowers can deduct various interest expenses, potentially leading to less taxable income.
