IRS Form 1099-INT “Interest Income” Explained

IRS Form 1099-INT, Interest Income, reports interest paid to you by banks, credit unions, brokerages and the U.S. Treasury. Payers generally issue it when interest totals $10 or more, but all taxable interest must be reported on your return, with or without a form.

Key Boxes

• Box 1, Interest income: taxable interest from savings, CDs, money market accounts, corporate bonds and similar sources
• Box 2, Early withdrawal penalty: penalties for cashing a CD early, deductible as an adjustment on Schedule 1
• Box 3, Interest on U.S. savings bonds and Treasury obligations: federally taxable but exempt from state income tax
• Box 4, Federal income tax withheld (usually backup withholding)
• Box 6, Foreign tax paid
• Box 8, Tax-exempt interest: municipal bond interest. It isn’t federally taxable but must still be reported, and it can affect how much of your Social Security is taxed.
• Box 9, Specified private activity bond interest: may be subject to the alternative minimum tax
• Boxes 10-13: market discount and bond premium adjustments

Where It Goes on Your Return

Taxable interest is reported on Form 1040. If your total taxable interest is more than $1,500, list each payer on Schedule B. Tax-exempt interest goes on its own line of Form 1040. Higher-income taxpayers may owe the 3.8% net investment income tax on interest.

Due Dates

Payers must furnish 1099-INT to recipients by January 31. Brokerages often include it in a consolidated statement in mid-February.

Common Questions

• Is interest on an online savings account taxable? Yes, it’s ordinary income in the year it’s credited to your account, even if you don’t withdraw it.
• What about U.S. savings bonds? You can report the interest each year or when the bonds are redeemed. Some savings bond interest used for higher education may be excludable (Form 8815).
• Interest on a seller-financed mortgage you hold? Report it on Schedule B with the buyer’s name, address and SSN.

Related: Form 1099-DIV, Dividends and Distributions.

Get Help From Diehl CPA

Tax rules change often, and the right answer depends on your full financial picture. Diehl CPA, led by Mark Diehl, CPA, CFE, prepares returns and builds tax plans for investors, retirees and closely held businesses. Learn about our tax return preparation and investment tax planning services, or contact us to talk through your situation.

This article is general information, not tax or legal advice for your specific situation. Updated October 2026.