# Interest on the federal debt, per tax dollar: working notes

Money & World, compiled 2026-07-21 from US Treasury primary data. Take it and
check us. Corrections: corrections@moneyandworld.com.

## What each column is

- **net_interest_usd** — the federal budget "Net Interest" outlay (function 900),
  full fiscal year. From the Monthly Treasury Statement, Table 9, the "Net
  Interest" line. Net interest is gross interest paid on the debt minus interest
  the government receives and minus interest credited to federal trust funds.
- **gross_interest_on_debt_usd** — total interest expense on the public debt
  outstanding, the sum of every fiscal-year-to-date line in Treasury's Interest
  Expense on the Public Debt Outstanding dataset at the September (year-end)
  reading. Includes interest credited to government account series (trust funds).
  Provided for FY2025 only.
- **total_receipts_usd** — total federal receipts, MTS Table 9 line 1.8.
- **individual_income_taxes_usd** — MTS Table 9, "Individual Income Taxes."
- **total_outlays_usd** — total net outlays, MTS Table 9 line 2.20.

## Sources (primary, machine-readable)

- Monthly Treasury Statement, Table 9 (Summary of Receipts by Source and Outlays
  by Function), Fiscal Data API. Each fiscal year read at record_calendar_month
  09, which reports the full year to date. FY2024 values are read from the
  prior-year column of the FY2025 September file and tie to the FY2024 file.
  https://fiscaldata.treasury.gov/datasets/monthly-treasury-statement/
- Interest Expense on the Public Debt Outstanding, Fiscal Data API.
  https://fiscaldata.treasury.gov/datasets/interest-expense-debt-outstanding/

API endpoints used:
- https://api.fiscaldata.treasury.gov/services/api/fiscal_service/v1/accounting/mts/mts_table_9
- https://api.fiscaldata.treasury.gov/services/api/fiscal_service/v2/accounting/od/interest_expense

## FY2025 gross interest, as summed

Public issues: 973,673,123,955.84. Government account series (intragovernmental):
246,352,158,674.47. Total: 1,220,025,282,630.31. The gap between this gross total
and net interest of 970,358,886,994 is about 250bn, most of it interest the
Treasury credits to the Social Security, Medicare and federal pension trust funds,
which is money the government owes itself.

## Caveats

- These are receipts and outlays as reported in the MTS, the cash-basis budget
  totals. They are final for closed fiscal years.
- "Cents per income tax dollar" divides net interest by individual income tax
  receipts alone. That is a deliberate framing, explained in the article: it is
  not the standard "share of total receipts" figure, and it is larger because
  individual income tax is under half of all receipts.
- Ratios are rounded to two decimals. Dollar columns are exact to the dollar.