US debt reached $40tn for the first time on Wednesday, the US treasury department said, after the government deficit doubled over the last decade.

The treasury’s latest debt balance showed $40.047tn on Tuesday afternoon, the highest in US history.

The milestone marks years of government spending that grew under both Donald Trump and Joe Biden. During his first term, Trump approved $8.4tn worth of debt, with a huge chunk going to Covid-19 relief spending, while Biden approved $4.3tn worth of debt, according to the Committee for a Responsible Federal Budget.

In fiscal year 2026, which started in October 2026, $1.8tn has been added to the debt so far, with a big chunk of new government spending dedicated to tariff refunds, which have totaled $100bn so far, according to the Bipartisan Policy Center.

Government spending watchdog groups have anticipated for weeks the US surpassing the $40tn threshold after debt reached $39tn in March.

“For perspective, it took nearly 200 years for America’s gross debt to reach $1 trillion for the first time in 1981,” said Maya MacGuineas, president of the Committee for a Responsible Federal Budget in a statement. “$40 trillion 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. 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.”

The threshold was breached as Congress, currently out of session, remains at an impasse over its latest spending bill. The US House and Senate passed two different bills that would fund the federal government, which is scheduled to shut down on 30 September if a bill isn’t adopted by both chambers and signed by the president.

Earlier on Wednesday, the US treasury announced it would double its buyback of government debt after the bond market balked at ongoing inflation and continued conflict between the US and Iran. Though the move doesn’t increase the debt, it highlights the growing struggle the US is having in attracting investors to help take on its debt.