Deep Dive: Interest on the debt cost $609.2 billion in cash in fiscal 2025, about $1.67 billion a day

Where the interest money goes

Interest is not paid to a single place. Treasury securities are held by mutual funds, pension funds, banks, money market funds, insurance companies, households buying through TreasuryDirect, the Federal Reserve, and foreign governments and investors. The largest foreign holders in the Treasury International Capital data compiled in the Ledger research records, dated July 2026, were Japan at about 1.104 trillion dollars, the United Kingdom at about 998 billion dollars, and mainland China at about 618 billion dollars. The Federal Reserve held about 4.49 trillion dollars in Treasury securities in the same records, and currently remits nothing back to the Treasury because of past losses on its portfolio, per the research records.

The $609.20 billion fiscal 2025 figure is cash interest recorded in the Daily Treasury Statement for the fiscal year ending September 30, 2025. It is a flow figure, money that left the Treasury during that year, as distinct from the debt total itself, which is a stock figure measured on a single date. Keeping the two apart avoids the most common misreading of this topic: the interest cost in any year depends on the size of the debt and on the mix of rates locked in across every security still outstanding, some sold years ago at lower rates and some sold recently at higher ones.

Why the cost is rising in plain terms

Two facts drive the trend. First, the base keeps growing. The debt rose from 37.64 trillion dollars at the September 30, 2025 fiscal year end to $40,343,879,238,035.67 on October 13, 2026, and it grew by $452,105,244,014 in the 64 days ending October 13 alone, an average of about $81,761 per second. More debt outstanding means more securities paying interest.

Second, maturing securities are refinanced at current auction rates. Bills mature within a year, so the bill portion of the debt reprices quickly. Notes and bonds lock their rates for years, so their repricing arrives slowly, as each older security matures and is replaced. The result is a lagged, steady transmission: market rates set at auction today shape the interest line for years, in both directions.

For scale, the fiscal 2025 cash interest total of $609.20 billion is larger than the full year contract obligations of most individual departments, and it is paid before any program spending decision is made in a given year, because the securities were sold in earlier years. It is, in that sense, the price of past borrowing arriving on a schedule, recorded line by line in the Daily Treasury Statement withdrawal data that the Ledger tracks each day.

Data vintage: interest total is fiscal 2025, from Daily Treasury Statement lines compiled October 2026. Foreign holder figures are July 2026 Treasury International Capital data as compiled in the Ledger research records. Debt figures are October 13, 2026.

Sources

1. U.S. Department of the Treasury, Fiscal Data, Daily Treasury Statement dataset: https://fiscaldata.treasury.gov/datasets/daily-treasury-statement/daily-treasury-statement

2. U.S. Department of the Treasury, Fiscal Data, Debt to the Penny dataset: https://fiscaldata.treasury.gov/datasets/debt-to-the-penny/debt-to-the-penny