The U.S. national debt has reached a historic milestone, surpassing $40 trillion for the first time ever, according to data from the Treasury Department released on Wednesday, which showed the gross national debt at $40,047,425,768,420.22 as of August 18 [1]. CNBC reports the total U.S. government debt at $40.05 trillion as of Tuesday, noting that this figure has more than doubled from $19.4 trillion a decade ago [2]. The debt crossed the $39 trillion threshold about five months ago in March, following the $38 trillion mark in October 2025 [1].
The rapid increase in national debt is attributed to persistent federal budget deficits, surging interest costs due to both a larger debt burden and higher interest rates, and increased federal spending on Social Security and Medicare as the U.S. population ages [1][2]. The Congressional Budget Office (CBO) estimates that the gross national debt will rise to $63 trillion by 2036, with annual budget deficits widening from about $2.1 trillion this fiscal year to $3.1 trillion a decade from now [1]. In July, the Treasury reported a $432.3 billion deficit, the highest monthly total since March 2021, and the year-to-date shortfall is nearing $1.8 trillion, higher than the same period a year ago [2].
Interest on the debt has become the largest budget expenditure outside of Social Security and Medicare, totaling nearly $1.2 trillion this year [2]. Michael A. Peterson, CEO of the Peter G. Peterson Foundation, emphasized the urgency of addressing the debt, stating, "The more debt we take on, the more interest costs we have to bear, which now even exceed the cost of national defense. And every trillion we add to our debt contributes to higher interest rates and inflation, increasing the mortgages, car loans and credit card bills of all Americans" [1].
Market implications have been significant, with Treasury yields surging since late June to levels not seen since before the global financial crisis [2]. The Treasury Department has responded by increasing the size of its repurchases at the long end of the yield curve [2]. Concerns over the debt-and-deficit situation, along with factors such as surging corporate bond issuance and uncertainty over the Federal Reserve's inflation-fighting stance, have contributed to higher yields [2]. The CBO warns that debt held by the public is projected to grow faster than U.S. GDP in the coming years, potentially slowing economic growth, reducing private investment, and increasing the risk of a fiscal crisis [1].
CONCLUSION
The U.S. national debt's unprecedented rise to over $40 trillion underscores mounting fiscal challenges, with soaring interest costs and persistent deficits driving market volatility. Both sources highlight the risk of higher borrowing costs and potential economic headwinds if current trends continue. Policymakers face increasing pressure to address the nation's fiscal trajectory to mitigate further market and economic risks.