The Treasury's latest daily cash and debt balances statement showed total public debt outstanding at $US40.047 trillion, a total that includes Treasury securities held by the public of $US32.266 trillion and intra-governmental debt holdings of $US7.782 trillion.
The federal government's IOU has now more than doubled in less than a decade, from $US19.95 trillion when President Donald Trump was sworn in for the first time in January 2017.
Roughly one-third of that increase occurred during two years of frantic government borrowing to fund the COVID-19 pandemic responses undertaken by Trump and former President Joe Biden, while the fiscal policy choices of both presidents combined with long-running tax-and-spending imbalances to account for the rest.
Budget watchdog groups have been anticipating the crossing of the threshold for weeks and have issued stark warnings that a full-blown debt crisis could erupt unless politicians confront an unsustainable fiscal outlook and raise taxes, cut spending or both.
"Forty trillion dollars of debt doesn't exist solely on the government's ledgers; it is felt throughout the economy and finds its way to the pocketbooks of people one way or another," said Maya MacGuineas, president of the nonpartisan Committee for a Responsible Federal Budget.
"The more we borrow, the more we exacerbate inflation, squeeze out other priorities in the budget, and leave ourselves vulnerable to emergencies at home and turmoil abroad."
She noted the $US40 trillion figure was reached less than five months after debt reached $US39 trillion, and has quadrupled in less than 20 years after taking until 1981 to reach $US1 trillion for the first time.
"It is staggering how predictable the fiscal decline of a global power can become," MacGuineas added.
Global US creditors may already be growing wary. Days after a $US25 billion auction of 30-year Treasury bonds went off at the highest yield since 2021, yields on so-called long bonds on Tuesday hit their highest levels in nearly two decades as investors demanded greater compensation in the face of hefty US government bond issuance.
On Wednesday, US Treasury Secretary Scott Bessent took a bold step to push long bond yields back, announcing a doubling of buyback sizes for 10- to 30-year Treasuries to at least $US4 billion per operation.
The term premium for 10-year Treasuries - a measure of how much of the security's overall yield is accounted for by the perceived risk of holding them over a decade - rose this week to its highest in more than a dozen years.
Since Trump took office a second time in January 2025, the US debt load has increased by $US3.8 trillion, for total growth of $US11.6 trillion across his two terms so far.
Public debt increased by $US8.4 trillion during Biden's term, also marked by heavy COVID-19 recovery spending, but driven as well by big-ticket outlays for infrastructure investment, clean energy subsidies and other priorities championed by his Democratic Party.
The Committee for a Responsible Federal Budget estimates the policy choices of Trump and Biden have increased the federal debt trajectory beyond what would have accumulated under the existing spending statutes when each took office.
