Net Interest Hit $1.05 Trillion in Fiscal 2026, Up 8.4 Percent. September Put Medicare Back Ahead of It.
Treasury's final statement shows interest took about 19 cents of every revenue dollar and equaled 53 percent of the $1.99 trillion deficit. Revenue grew 3.2 percent.
By Priya Kanth, Business & Economy
· 4 min read · Updated
Key Takeaways
- •Net interest was $1.052 trillion in fiscal 2026, up 8.4 percent from $970 billion, while revenue rose 3.2 percent and outlays 5.5 percent.
- •Interest equaled 52.8 percent of the $1.992 trillion deficit and about 19 cents of every dollar of federal revenue.
- •Net interest rose $81 billion, 37 percent of the $217 billion widening in the deficit.
- •Interest led Medicare through August ($1.017 trillion to $979 billion) but finished $21 billion behind it for the year.
- •CBO Director Phillip Swagel said growth alone is unlikely to stabilize the debt, while Treasury Secretary Scott Bessent said 3 percent growth would, per Fortune.
Net interest cost the federal government $1.052 trillion in fiscal 2026, up 8.4 percent from $970 billion a year earlier, according to Treasury's Monthly Treasury Statement for September. Revenue grew 3.2 percent. Spending grew 5.5 percent. Interest outran both.
The short answer
The government collected $5.40 trillion and spent $7.40 trillion in the year that ended September 30, leaving a $1.99 trillion deficit. Net interest took about 19 cents of every dollar collected, or roughly $2.88 billion a day. Without it, the deficit would have been $941 billion.
$1.052T
Net interest, fiscal 2026
Up 8.4 percent from $970 billion in fiscal 2025. Interest equals 52.8 percent of the deficit.
Interest explains 37 percent of the wider deficit
The deficit grew $217 billion, from $1.775 trillion to $1.992 trillion. Net interest rose $81 billion, which is 37 percent of that increase. Receipts rose $169 billion, but not evenly. Individual income taxes climbed 7.1 percent to $2.846 trillion. Corporate income taxes fell 15.6 percent to $381 billion, and customs duties fell 11.1 percent to $173 billion. Treasury's tables show the declines but do not say why they happened.
Spending carried the rest. Outlays reached $7.396 trillion against $7.010 trillion a year earlier. Social Security rose 5.5 percent to $1.667 trillion, and defense rose 5.3 percent to $965 billion.
Medicare moved back ahead of interest in September
Through August, Treasury's spending-by-function table had net interest at $1.017 trillion, ahead of Medicare at $979 billion. The full year reversed that. Medicare finished at $1.073 trillion, up 7.6 percent, and interest at $1.052 trillion. The gap is $21 billion.
Subtracting the August year-to-date figures from the full-year ones, Medicare spent about $93 billion in September and net interest about $35 billion. The first eleven months of interest averaged about $92 billion a month. The lines reviewed for this story do not explain why September was so small, and this is arithmetic on two cumulative figures, not a number Treasury reports directly. An earlier Trestlewire report that interest ran ahead of Medicare was based on data through August. It does not hold for the full year. Interest still finished $87 billion ahead of defense.
A third of public debt reprices within a year
Fortune, which also analyzed the Treasury release, reported that gross interest on Treasury debt reached $1.36 trillion at an average rate of 3.53 percent, more than double the 2021 rate. Fortune also reported that more than $10 trillion of debt held by the public, about a third of the total, matures within 12 months and has to be refinanced at current yields. It put the 10-year Treasury yield above 5 percent, higher than the 4.1 to 4.4 percent range the Congressional Budget Office had forecast. Net interest is a payment to holders of Treasury securities. The statement does not say how much went to foreign holders.
The gap between the average rate and the market yield is the mechanism. Debt issued when yields were low keeps its old coupon until it matures. Each maturing bond swaps a cheaper rate for a dearer one, so the average rate drifts up even if yields stop rising.
Growth is the argument, and the CBO doubts it
Treasury Secretary Scott Bessent said at Southern Methodist University that 3 percent growth lets the country grow its way out of the problem, Fortune reported. CBO Director Phillip Swagel disagreed in the same reporting. He said growth will help but is unlikely to stabilize the debt by itself. At interest rates of 4 to 5 percent, he estimated, stabilizing it would take nominal GDP growth of 7 to 8 percent, or 5 to 6 percent after inflation. Real growth was 2.2 percent in the second quarter, and Wall Street expects 2.5 percent for the full year, according to Fortune.
Maya MacGuineas, president of the Committee for a Responsible Federal Budget, which advocates deficit reduction, argues the loop feeds itself: more debt pushes rates up, higher rates raise interest, and interest adds debt. That is her reading of cause and effect, not a Treasury finding.
What the statement cannot tell us yet
These are cash figures for one year. A single year cannot separate a trend from a bad stretch, though interest has now grown faster than revenue, outlays and the economy's roughly 6 percent nominal growth, per Fortune's comparison. The October statement, the first of fiscal 2027, will show whether September's small interest figure was a timing swing or something that repeats.
- Net interest
- Federal deficit
- Treasury
- Medicare
- Fiscal 2026
- Scott Bessent
Sources
- 01Monthly Treasury Statement, September 2026 (tables 5 and 9), U.S. Treasury, Bureau of the Fiscal Servicefiscaldata.treasury.gov
- 02U.S. debt interest payments in fiscal 2026, Fortunefortune.com
Corrections
No corrections have been made to this article.
About the reporter
Business & Economy Reporter, Trestlewire
Before I was a journalist, I spent five years as an equity research analyst, building spreadsheet models that nobody outside a trading floor would ever see. I learned two things in those years: that a compelling story and an accurate one are not always the same thing, and that almost every business narrative worth writing about is sitting inside a spreadsheet somewhere, waiting for someone to open the file.
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