The federal government’s total public debt outstanding topped $40 trillion on September 24, reaching $40,068,807,991,924.84, according to Treasury Department data published daily. The threshold arrives as the Congressional Budget Office projects net interest payments on that debt will reach $1.0 trillion in the current fiscal year, a cost that a separate GAO review says has already surpassed defense spending.
What $40 trillion in federal debt doesn’t cover: Treasury’s own figures stop at the federal ledger, and The Senior Property Tax & Home-Cost Relief Kit’s rundown of the 5 kinds of property-tax relief covers the state and local programs that ledger leaves out entirely. Look up which property-tax relief applies →
The number Treasury published
Treasury’s Debt to the Penny dataset, updated every business day, recorded total public debt outstanding of $40,068,807,991,924.84 as of the September 24 record date, a figure that combines debt held by the public with debt one part of the government owes another. The dataset does not itself explain what drove the debt past $40 trillion; it simply reports the balance as of that date, the same way it has reported a new balance every business day since the government began publishing the series. Treasury separately publishes the average interest rate paid across its outstanding securities through its interest expense and average interest rates dataset, the underlying detail behind how quickly interest costs on that balance are climbing.
Interest costs are the part rising fastest
The debt total is only part of the picture. In its most recent long-term budget outlook, the Congressional Budget Office projected net interest spending would reach $1.0 trillion in the current fiscal year, equal to 3.3 percent of gross domestic product, and grow to $2.1 trillion, or 4.6 percent of GDP, by 2036. That trillion-dollar interest bill is money the government pays simply to service debt already issued, before a single dollar goes toward any benefit, grant or agency budget for the current year. In testimony delivered March 11, CBO put federal debt held by the public at 101 percent of GDP this year, on a path to 120 percent of GDP by 2036 under current law, meaning the debt would be larger than the entire American economy produces in a year and then some.
GAO says interest already outpaces defense spending
The trajectory concerns GAO as much as CBO. A GAO review of the nation’s fiscal health, led by Director of Strategic Issues Jeff Arkin, found that net interest spending in fiscal year 2025 had already surpassed federal defense spending, and separately put publicly held debt at $31.3 trillion by April 2026, on pace to reach 123 percent of GDP by 2036 under current policy, or as high as 251 percent of GDP by 2056 if current tax and spending policies do not change. The same report projected the Social Security and Medicare trust funds could be depleted in 2032 and 2033, respectively, timelines that arrive well before several of the debt projections built around them. GAO’s central recommendation is that Congress develop a comprehensive fiscal strategy, including formal fiscal rules, an actual consensus on deficit reduction, and a financing plan for the trust funds, before either one runs out.
What the total does and doesn’t mean for a household budget
None of these figures translate directly into a bill an individual household receives. Federal interest costs are paid out of general revenue, not billed to any one taxpayer, and Treasury’s securities auctions have continued without disruption as the debt has grown. Part of the $40 trillion figure is intragovernmental debt, money one federal account owes another, such as the Social Security trust funds’ holdings of Treasury securities, while the rest is debt held by the public in the form of bills, notes and bonds sold to investors, foreign governments and the Federal Reserve, the same breakdown Treasury’s dataset reports for every single record date it publishes. What the trend does mean, according to GAO’s fiscal-health reviews, is less room in future federal budgets for the programs that do reach households directly, from benefit adjustments to disaster and infrastructure grants, as a larger share of every tax dollar collected goes toward interest rather than services, a dynamic GAO says compounds each year the government continues borrowing at current rates without a plan to change course.
Where the debt figure updates next
Treasury updates the Debt to the Penny figure every business day, and the next milestone, whatever threshold comes after $40 trillion, will already be reflected in the dataset before any single agency or lawmaker announces it. CBO and GAO, for their part, revisit their long-term projections roughly twice a year, meaning the interest-cost and debt-to-GDP figures cited here are themselves due for another update within months, likely before the next round of federal budget deliberations concludes. None of the three sources cited here, Treasury, CBO or GAO, ties the $40 trillion threshold itself to a specific legislative deadline or a scheduled vote; the figure is simply where the running total stood on September 24, and it will keep moving upward regardless of what Congress does or does not decide next.
Local relief the federal debt figures don’t include
The debt total Treasury published does not touch the property-tax freezes, exemptions and utility assistance that states and counties run on their own, or the paperwork required to claim them. Those programs run on local calendars that have nothing to do with the federal ledger, and many require reapplying every year to keep the benefit current.
The Senior Property Tax & Home-Cost Relief Kit lists the 5 kinds of property-tax relief and provides an application log and renewal calendar for tracking each program’s own deadline.
Compare the property-tax relief programs in The Senior Property Tax & Home-Cost Relief Kit.
This article was produced with AI assistance and checked against the primary sources linked above.
Warren Cohen is a finance writer based in Phoenix, Arizona, covering personal finance topics including credit, banking, and beginner investing. He earned his degree in business administration from Arizona State University and began his career working in consumer finance, where he gained direct experience with lending and credit systems. He now writes for personal finance websites and fintech platforms, focusing on clear, practical content that helps readers make informed financial decisions.
