Line 2b of Form 1040 is where you report your total taxable interest income for the year. That figure is the sum of every taxable interest payment you received, from bank accounts, CDs, bonds, money market accounts, seller-financed mortgages, and anything else that paid you interest, minus a few specific adjustments the IRS allows. It flows into your adjusted gross income, so getting it right matters for both your tax bill and your eligibility for credits and deductions.
What Counts as Taxable Interest
Taxable interest is money someone paid you for the use of your funds. The IRS treats nearly all interest as taxable, and you owe tax on it whether you withdrew it or left it sitting. If interest was credited to an account and you could have taken it out, it counts as received.1Internal Revenue Service. Publication 550 (2025), Investment Income and Expenses
The common sources that belong on Line 2b:
- Savings accounts, interest-bearing checking accounts, and certificates of deposit
- Corporate bonds, Treasury bonds, and Treasury bills
- Money market accounts at banks or brokerages
- Interest on a personal loan you made to someone else, including seller-financed mortgages
- Original Issue Discount (OID) on bonds you hold, reported each year even if you won’t see the cash until maturity
If you financed a property sale, the interest portion of each installment payment the buyer sends you is taxable interest and belongs on Line 2b.
Interest That Does Not Belong on Line 2b
Some interest is federally tax-exempt and stays off this line. The biggest category is interest from state and local government bonds, often called municipal bonds. That interest goes on Line 2a, not Line 2b. The distinction matters because the IRS still uses the Line 2a figure for other calculations, including how much of your Social Security benefits are taxable.
Interest earned inside a traditional IRA, Roth IRA, or 401(k) is not reported on Line 2b either, because it is not currently taxable. Interest on Series EE or Series I savings bonds used for qualified higher education expenses can also be excluded, subject to income phaseouts.
The Documents You Need
The main form is the 1099-INT. Banks, credit unions, and other payers issue one whenever they paid you $10 or more in interest during the year.2Internal Revenue Service. About Form 1099-INT, Interest Income Box 1 shows ordinary taxable interest. Box 3 shows interest on U.S. savings bonds and Treasury obligations, which is federally taxable (and goes on Line 2b) but exempt from state and local tax.
If you hold a bond issued at a discount, you’ll also receive a 1099-OID. The OID amount is treated as interest and gets added to your Line 2b total.
Here is the part that catches people: you owe tax on all your interest, even without a 1099. If a bank paid you $8, no form was generated, but the $8 is still taxable.3Internal Revenue Service. Topic No. 403, Interest Received The same applies to interest from a private loan or from a partnership reported on a Schedule K-1. Add every source together, whether or not a form was issued.1Internal Revenue Service. Publication 550 (2025), Investment Income and Expenses
Adjustments That Reduce Your Line 2b Total
Not every dollar on your 1099s ends up on Line 2b. Three common situations let you subtract interest before entering your final number. Each adjustment is made on Schedule B: list the full interest amount from the 1099, then subtract the adjustment with a labeled entry, and carry the net figure to Line 2b.
Nominee Interest
If a 1099-INT was issued in your name but part of the interest actually belongs to someone else, you received that portion as a nominee. List the full 1099 amount on Schedule B, then subtract the other person’s share with the label “Nominee Distribution.”4Internal Revenue Service. Instructions for Schedule B (Form 1040) You also need to issue a 1099-INT to the actual owner (unless they are your spouse) and file that form with the IRS.
Accrued Interest on Purchased Bonds
When you buy a bond between interest payment dates, you typically pay the seller for interest that accrued before you owned it. When the next coupon arrives, your 1099-INT includes that accrued portion even though it was really the seller’s income. List the full amount on Schedule B, then subtract the accrued interest you paid at purchase, labeled “Accrued Interest.”5Internal Revenue Service. Instructions for Schedule B (Form 1040)
Amortizable Bond Premium
If you bought a taxable bond for more than its face value, the excess is bond premium. You can elect to amortize that premium and use it to offset the interest the bond generates each year. The election applies to all taxable bonds you hold during the year and going forward. You make it by offsetting the interest on your return and attaching a statement that you are electing under Treasury Regulation 1.171-4.6eCFR. 26 CFR 1.171-4 – Election to Amortize Bond Premium on Taxable Bonds
When You Have to File Schedule B
Schedule B is the worksheet where you list each source of interest before totaling it for Line 2b. You must file it if any of these apply:7Internal Revenue Service. About Schedule B (Form 1040), Interest and Ordinary Dividends
- Your taxable interest exceeds $1,500 for the year
- You received interest from a seller-financed mortgage where the buyer used the property as a personal residence
- You are claiming the education savings bond exclusion for Series EE or I bonds issued after 1989
- You have a financial interest in or signature authority over a foreign financial account
If your taxable interest is $1,500 or less and none of the other triggers apply, you can skip Schedule B and enter the total directly on Line 2b. You still need to use Schedule B if you’re taking any of the adjustments above, because that is where the subtraction is shown.
Foreign Accounts and a Child’s Interest
Interest earned in a foreign bank account still goes on Line 2b like any other taxable interest. The foreign angle creates separate reporting on top of your return. If the combined value of your foreign financial accounts exceeded $10,000 at any point during the year, you must file FinCEN Form 114 (the FBAR) with the Financial Crimes Enforcement Network, filed separately from your tax return.8Internal Revenue Service. Report of Foreign Bank and Financial Accounts (FBAR) At higher asset levels, Form 8938 is filed with your return as well.9Internal Revenue Service. Do I Need to File Form 8938, Statement of Specified Foreign Financial Assets Part III of Schedule B is where you answer the foreign-account question.
If a child earned interest, you have a choice. When a child’s only income is interest and dividends totaling less than $13,500, you can elect to report it on your return using Form 8814 instead of filing a separate return for the child.10Internal Revenue Service. Topic No. 553, Tax on a Child’s Investment and Other Unearned Income If you make that election, the child’s taxable interest is folded into yours. Otherwise the child files their own return, and depending on the amount, the “kiddie tax” rules apply and some of it is taxed at your marginal rate.
What Happens If You Get It Wrong
The IRS does not rely on the honor system here. Every 1099-INT your bank sent you also went to the IRS. Its Automated Underreporter program matches third-party reports against what you put on your return, and a mismatch generates a CP2000 notice proposing additional tax.11Internal Revenue Service. Topic No. 652, Notice of Underreported Income – CP2000
If the IRS determines you were negligent or disregarded the rules, the accuracy-related penalty is 20% of the underpaid tax. Failing to include income shown on a 1099 is specifically listed as an example of negligence.12Internal Revenue Service. Accuracy-Related Penalty Where the IRS can show fraud, the penalty rises to 75% of the underpayment attributable to the fraud, and the burden shifts to you to prove any portion was not fraudulent.13Office of the Law Revision Counsel. 26 USC 6663 – Imposition of Fraud Penalty Interest also runs on any unpaid tax from the original due date until you pay.
Before filing, check every 1099-INT against your own records, add in any taxable interest that came without a form, apply any adjustments on Schedule B, and carry the net total to Line 2b. If you received interest you forgot about, the IRS almost certainly already has a copy of the form.