This tool allows users to calculate the approximate debt-service (or interest) costs associated with changes in federal revenues and outlays in relation to the Congressional Budget Office's 10-year budget projections (or budget baseline). Specifically, users can see how increases or decreases in net spending arising from a policy change would affect interest outlays, deficits, and debt—in billions of dollars and as a percentage of gross domestic product. Also provided are the projected interest rates that the federal government would effectively pay on any new borrowing arising from the policy change, and, in a static table, the Treasury yields that play a large role in those projected rates.
Details
Every year, CBO publishes projections of what the federal budget and the economy would look like in the current year and over the next 10 years if current laws governing taxes and spending generally remained unchanged. The budget projections are the baseline the agency uses when estimating the budgetary effects of proposed legislation (analyses known as cost estimates).
This tool is based on the latest baseline projections in CBO's Budget and Economic Outlook series, which were released in February 2026. In CBO's baseline projections, net outlays for interest are calculated by estimating how much debt the Treasury would need to issue to finance government operations and the interest rates that it would pay on that debt. Projections of two of those rates are reproduced here in a separate table.
Limitations
This tool does not incorporate dynamic effects stemming from changes in economic performance; specifically, interest rates do not change on the basis of user-specified changes in revenues or outlays.
The tool is a simplified version of the model that CBO uses for projecting debt-service costs when updating its baseline projections to incorporate changes in revenues or outlays. The results generated do not constitute an official CBO estimate.
Effects of changes in federal revenues and outlays
Budget outlook with changes
Billions of dollars
| Value estimated | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Revenues | |||||||||||||
| CBO's baseline | |||||||||||||
| Increase or decrease (-) | |||||||||||||
| User-specified scenario | |||||||||||||
| Outlays | |||||||||||||
| CBO's baseline | |||||||||||||
| Increase or decrease (-) | |||||||||||||
| User-specified scenario | |||||||||||||
| Deficit | |||||||||||||
| CBO's baseline | |||||||||||||
| Increase (-) or decrease | |||||||||||||
| User-specified scenario | |||||||||||||
| Debt held by the public | |||||||||||||
| CBO's baseline | |||||||||||||
| Increase or decrease (-) | |||||||||||||
| User-specified scenario | |||||||||||||
Data source: Congressional Budget Office, The Budget and Economic Outlook: 2026 to 2036 (February 2026).
n.a. = not applicable.
Treasury yields
Percent
| Year | 3-month Treasury bills |
10-year Treasury notes |
|---|---|---|
Data source: Congressional Budget Office, The Budget and Economic Outlook: 2026 to 2036 (February 2026).
These rates, which are for two of the several types of Treasury securities that affect debt-service calculations, are fiscal year averages of the rates presented in The Budget and Economic Outlook: 2026 to 2036.
Definitions
Debt held by the public consists mainly of securities that the Treasury issues to raise cash to fund the operations and pay off the maturing liabilities of the federal government that tax revenues are insufficient to cover.
Effective marginal borrowing rate refers to the annualized interest rate on the additional securities the Treasury would issue (or retire) because of the change in revenues and outlays.
Related Publications
About this Interactive Tool
Casey Labrack and Avi Lerner developed this interactive tool with guidance from Barry Blom. Jeffrey Kling, Christina Hawley Anthony, and Sam Papenfuss reviewed it; Lora Engdahl edited it; and Maria Aquino and Annette Kalicki integrated it into CBO's website and prepared it for release.
This page was last updated on March 16, 2026.