Updated September 30, 2026. Quick answer: Box 3 of Form 1099-INT is interest on U.S. Savings Bonds, Treasury bills, Treasury notes and Treasury bonds. The payer keeps it out of Box 1, so a T-bill investor should look in Box 3.
More IRS forms and schedules, read line by line: Form 8815 instructions.
Schedule A and Schedule B (Form 1040) for 2025, read line by line: Schedule B lines 1 to 4.
Read box by box from the IRS form text: Form 1099-OID boxes explained, Form 1099-OID box 1 and Form 1099-OID box 8.
The IRS form or worksheet behind this, read line by line: Schedule B instructions.
Price a bond by its issue month: I bond calculator.
The Treasury form for cashing a paper savings bond, with the cash-or-hold decision first: FS Form 1522 and the cash-or-hold decision.
What the instruction says
The instruction is “Enter interest on U.S. Savings Bonds, Treasury bills, Treasury notes, and Treasury bonds. Do not include in box 1.” The 1099-INT instructions read here are the January 2024 revision (combined with Form 1099-OID), which is the edition irs.gov shows as current for those forms. Those are instructions to the payer that files the form, so they show what a box is meant to hold, not what tax follows from it. These instructions say nothing about whether the interest is taxed by your state, so this page does not decide that.
Bond premium on a Treasury obligation
A premium paid for a Treasury obligation is handled in Box 12. The Box 3 instruction says “For a taxable covered security acquired at a premium, see Box 12. Bond Premium on U.S. Treasury Obligations, later.” Box 12 is on the Box 10 to 13 page.
Backup withholding reaches Box 3
The Box 4 instruction names the boxes backup withholding applies to: “you must backup withhold on payments required to be reported in box 1 (which may be reduced by the amount reported in box 2), box 3, and box 8 on this form.” Box 4 is on the Box 4 to 7 page.
Related CMG pages
For the state tax question on T-bill interest see T-bill interest and state income tax. For I bonds see the I bond interest reporting election.
Common mistakes
- Looking for Treasury interest in Box 1. The instruction says not to include it there.
- Assuming this page tells you a state will not tax the interest. These instructions are silent on it.
- Missing the separate premium box. Premium on a Treasury obligation is reported in Box 12.
Related: 1099-INT Box 1 Interest Income: What Counts, 1099-INT Box 10 to 13: Market Discount and Bond Premium, and T-bill interest and state income tax.
Every box in one place: the 1099-DIV, 1099-INT and 1099-B boxes table. If your withdrawal came from an IRA or 401(k), see the Form 1099-R Box 7 codes.
Sources
- IRS, Instructions for Form 1099-DIV (Rev. January 2024): irs.gov/pub/irs-pdf/i1099div.pdf
- IRS, Instructions for Forms 1099-INT and 1099-OID (Rev. January 2024): irs.gov/pub/irs-pdf/i1099int.pdf
- IRS, Instructions for Form 1099-B (2026): irs.gov/instructions/i1099b
Source: the IRS instructions for the filer of each form, read at irs.gov on September 30, 2026. General information, not tax advice. Your own facts decide the outcome, and a preparer, the account provider or the IRS is the right place to confirm anything consequential.