US Treasury data released on Wednesday, August 19, showed national debt had crossed $40 trillion. As investors focus on rising federal deficits, higher interest costs and pressure in the Treasury bond market.

The United States' gross national debt has crossed $40 trillion for the first time, marking a new milestone for the world's largest economy and renewing concerns over Washington's long-term fiscal path. Treasury data showed total public debt outstanding at about $40.047 trillion at the close of Tuesday, including roughly $32.266 trillion in Treasury securities held by the public and $7.782 trillion in intragovernmental holdings.

The debt has more than doubled from about $19.95 trillion when Donald Trump first entered the White House in January 2017. A significant share of the increase came during emergency borrowing linked to the COVID-19 pandemic, while tax policy, government spending and long-running structural deficits have continued pushing the total higher.

The federal government regularly spends more than it collects in revenue, requiring the Treasury to borrow to finance the gap. Rising costs for Social Security, Medicare, Medicaid and other mandatory programmes are adding to pressure as America's population ages.

Interest expenses have become another major burden. Reuters reported that interest costs reached about $1.1 trillion and, during the first 10 months of fiscal 2026, moved above Medicare spending to become the second-largest federal budget item after Social Security.

The Congressional Budget Office projected a fiscal 2026 deficit of about $1.9 trillion and debt held by the public of approximately $32.1 trillion at the end of the fiscal year. CBO's projections also show federal debt continuing to rise over the next decade if current tax and spending laws broadly remain unchanged.

The $40 trillion milestone comes during heightened stress in the US bond market. Long-term Treasury yields have climbed as investors demand higher returns to hold government debt amid concerns about inflation, heavy borrowing and the fiscal outlook.

The 30-year Treasury yield reached 5.34% on Tuesday, its highest level since 2007. Treasury Secretary Scott Bessent responded by announcing that buybacks of 10- to 30-year Treasury securities would be doubled to at least $4 billion per operation between September 9 and November 4. The announcement helped push long-term yields lower, although analysts cautioned that it does not resolve the underlying deficit problem.

Higher Treasury yields can affect the broader economy because they influence mortgage rates, auto loans, corporate financing and other borrowing costs. Sustained high rates also make refinancing federal debt more expensive.

Crossing $40 trillion does not automatically mean the United States is entering a debt crisis. Economists often focus more closely on debt held by the public, deficits relative to gross domestic product and the government's ability to service its obligations.

Still, the symbolic milestone has intensified warnings from fiscal policy experts. The combination of large annual deficits, ageing-related spending, tax and spending decisions and elevated interest costs could make future borrowing increasingly expensive.

For households and businesses, the biggest risk is not the headline figure alone but the possibility that persistent government borrowing keeps interest rates elevated and limits room for Washington to respond to future recessions or emergencies. The debate over taxes, spending and entitlement reform is therefore expected to remain central to US economic policy as federal debt moves beyond $40 trillion.