The United States has reached a debt milestone that highlights one of the biggest economic challenges facing Washington: the government is borrowing at a pace that is becoming increasingly difficult to sustain.
Total US debt outstanding reached $40.047 trillion on Tuesday, according to the Treasury Department’s latest daily cash and debt balances statement.
The figure includes $32.266 trillion in Treasury securities held by the public and another $7.782 trillion in intragovernmental debt.
The debt has more than doubled in less than a decade.
When Donald Trump entered the White House for the first time in January 2017, the federal government’s debt stood at $19.95 trillion.
The increase reflects several overlapping factors, including emergency borrowing during the Covid-19 pandemic, large government spending programs, tax cuts and a structural imbalance between federal revenue and expenditure.
The US government has continued to run substantial budget deficits even after the pandemic emergency ended.
That means Washington must keep issuing Treasury securities to finance the gap.
Budget watchdog groups have warned that the problem is becoming increasingly difficult to ignore.
“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, in a Reuters report.
“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,” MacGuineas said.
She noted that debt had reached $40 trillion less than five months after crossing $39 trillion and had quadrupled in less than 20 years after taking until 1981 to reach $1 trillion.
“It is staggering how predictable the fiscal decline of a global power can become,” MacGuineas added.
The debt problem is about more than the $40 trillion figure
The size of the debt itself does not determine whether a country is facing a fiscal crisis.
For the US, the more important issue is the relationship between debt, economic growth, government revenue and the cost of servicing the borrowing.
The US has several advantages that other heavily indebted countries do not.
Treasury securities are considered among the world’s most important financial assets, while the dollar remains the dominant global reserve currency.
But those advantages do not eliminate the cost of borrowing.
As the debt stock grows, the government has to pay interest on a larger amount of outstanding securities. If interest rates are also high, the cost can rise rapidly.
That is already happening.
In the first 10 months of fiscal 2026, interest costs have overtaken Medicare spending to become the second-largest line item in the federal budget, behind Social Security.
“The scariest thing about this is how we’re starting to see the debt spiral begin,” Marc Goldwein, senior policy director for the Committee for a Responsible Federal Budget, which supports deficit reduction, said in a NYT report.
The concern is that interest payments can create a self-reinforcing cycle.
More debt generates more interest expenses, which increases the deficit.
A larger deficit then requires additional borrowing, pushing the debt even higher.
Why are interest rates so important?
The cost of US borrowing depends heavily on Treasury yields.
When investors demand higher yields to hold government bonds, the Treasury has to pay more to finance new borrowing and refinance maturing debt.
Long-term Treasury yields have recently climbed sharply.
The yield on 30-year Treasury bonds reached its highest level in nearly two decades after a $25 billion auction produced the highest yield for such securities since 2021.
Bond yields move inversely to prices, meaning rising yields reflect investors demanding greater compensation for holding long-term government debt.
The rise is significant because Treasury yields act as a benchmark for borrowing costs across the economy.
Higher long-term yields can push up mortgage rates, car loans and commercial borrowing costs. They can also make it more expensive for companies to finance investments.
For households, that can translate into higher monthly payments.
For businesses, it can reduce the attractiveness of new projects and expansion.
The Treasury is trying to manage some of these pressures.
Treasury Secretary Scott Bessent announced Wednesday that the department would double the size of buyback operations for 10- to 30-year Treasuries to at least $4 billion per operation.
The move could help support liquidity and demand in the longer-dated Treasury market, although it does not solve the underlying imbalance between federal spending and revenue.
Foreign investors are another concern
The US has historically been able to finance its deficits partly because Treasuries are in high demand among foreign governments, central banks and institutional investors.
But there are signs that some overseas investors are becoming more cautious.
Foreign investors hold nearly one-third of US Treasury securities, and demand has declined over the past year.
If foreign demand weakens while the Treasury continues issuing large amounts of debt, domestic investors may have to absorb more of the supply.
That could require the government to offer higher yields.
This is one reason investors are watching Treasury auctions closely.
A sustained rise in yields could increase the government’s interest burden and create additional pressure on the budget.
It could also influence the Federal Reserve’s policy environment.
While the Fed does not directly set long-term Treasury yields, higher government borrowing costs can affect broader financial conditions.
Social Security and Medicare are at the heart of the problem
One of the biggest challenges for policymakers is that much of the federal budget is difficult to cut.
The US spends roughly $7 trillion a year, with around 60% allocated to mandatory programs such as Social Security, Medicare, Medicaid and veterans’ benefits.
These programs generally grow with the number of eligible recipients and the cost of living.
The aging of the baby boom generation is putting additional pressure on the system.
More Americans are retiring and receiving Social Security benefits, while healthcare spending is also increasing.
Payroll and income tax revenues are not sufficient to cover all federal spending, leaving Washington dependent on borrowing.
This makes the debt issue more complicated than simply eliminating waste from government agencies.
Cutting discretionary spending can produce savings, but it does not address the largest structural drivers of expenditure.
That is why meaningful deficit reduction would likely require politically difficult decisions involving entitlement programs, taxes or both.
How much have Trump and Biden added to the debt?
The debt increase spans multiple administrations and political parties.
US public debt rose by about $7.8 trillion during Trump’s first term.
More than half of that increase occurred during the final nine months of his presidency, when the government borrowed heavily to finance the Covid-19 response.
Debt then increased by $8.4 trillion during Joe Biden’s presidency.
Biden’s administration continued pandemic recovery spending while also approving major investments in infrastructure, giving clean energy subsidies, and other priorities.
Since Trump returned to office in January 2025, the debt has increased by approximately $3.8 trillion.
Across his two terms, the increase is about $11.6 trillion.
The Committee for a Responsible Federal Budget estimates that policy choices under both administrations have pushed the country’s debt trajectory above what would have occurred under existing spending laws when each president took office.
The numbers therefore point to a bipartisan problem rather than one created by a single administration.
Trump’s tax cuts add another layer
Trump has promoted tax cuts as a way to encourage investment and economic growth, arguing that stronger economic activity will eventually generate additional government revenue.
But tax cuts can increase deficits in the short term if the resulting economic growth does not immediately compensate for lost revenue.
The Congressional Budget Office estimates that Trump’s One Big Beautiful Bill Act will add $4.7 trillion to the federal debt.
Another $1.1 trillion is associated with the interest costs of additional borrowing.
The 2025 fiscal-year budget was also notable because debt service costs exceeded Pentagon spending for the first time.
Trump’s administration has argued that some of the tax measures will eventually pay for themselves by stimulating investment.
Businesses have been allowed to immediately deduct certain factory construction and equipment costs.
The Joint Committee on Taxation estimates those provisions could reduce government revenue by around $100 billion this year.
Bessent has argued that the initial cost will eventually be offset by higher economic activity and future tax receipts.
Whether that happens will depend heavily on the strength of economic growth.
What about Trump’s spending cuts?
Trump has also attempted to reduce government spending through the Department of Government Efficiency, which promised to identify $1 trillion in savings.
The department says it has generated more than $200 billion in savings.
But the Government Accountability Office has questioned the reliability and transparency of those estimates.
More importantly, many of the administration’s spending cuts have targeted discretionary programs, which make up the smaller portion of the federal budget.
The largest expenditures — Social Security, Medicare, Medicaid and other mandatory programs — are harder to reduce without fundamental changes to eligibility or benefits.
That leaves policymakers with a difficult choice if they want to materially change the debt trajectory.
Tariffs have not provided the expected fiscal relief
The Trump administration had also looked to tariffs as an important source of government revenue.
Import duties initially generated billions of dollars, but that strategy has been disrupted by legal challenges.
The Supreme Court ruled that some of the tariffs were illegal, forcing the government to refund more than $160 billion to companies that had paid the duties.
The refunds contributed to customs receipts turning negative for the third consecutive month and helped push the July deficit to $432 billion, the fourth-highest monthly deficit in US history.
The deficit during the first 10 months of fiscal 2026 has already surpassed the entire fiscal 2025 deficit, with two months still remaining.
That leaves little evidence so far that tariffs can provide a durable solution to the government’s fiscal imbalance.
Can the US avoid a debt crisis?
The $40 trillion milestone does not mean the US is on the verge of default.
The Treasury continues to have deep access to global capital markets, and demand for US government debt remains substantial.
The bigger concern is the direction of travel.
If debt continues growing faster than the economy, while interest costs consume an increasing share of federal revenue, policymakers could eventually have less room to respond to recessions, wars or other emergencies.
Bessent has set a goal of reducing the federal deficit to 3% of GDP by 2028, from more than 6% when Trump took office.
But he acknowledged last week that the deficit trajectory was moving in the wrong direction this year.
He cited several factors, including higher military spending linked to the war with Iran, tariff refunds and weaker economic growth caused partly by higher energy prices.
The combination illustrates why fiscal consolidation is so difficult.
Even when policymakers attempt to reduce the deficit, unexpected events can quickly increase spending or reduce revenue.
For investors, the immediate question is not whether the US can repay $40 trillion of debt.
It is whether Washington can stabilize the debt burden before interest costs and mandatory spending consume an increasingly large share of the federal budget.
The $40 trillion milestone is therefore less a cliff edge than a warning sign. The US still has enormous economic and financial advantages, but every additional trillion dollars of debt makes the cost of inaction higher.
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