Interest earned is taxed as ordinary income in most cases, meaning the money your savings accounts, CDs, and bonds pay you is added to your wages and taxed at your regular federal rate for the year it was credited. A few sources get better treatment: interest on U.S. Treasuries is exempt from state and local tax, most municipal bond interest is exempt from federal tax, and Series EE and I savings bonds let you defer the tax for decades. High earners also owe an extra 3.8% surtax on top of the regular rate. How interest earned is taxed depends less on the amount than on the source, and the after-tax result can differ sharply between two accounts paying the same headline yield.
Ordinary Income Treatment for Most Interest
The default rule is simple. Interest from savings accounts, money market accounts, certificates of deposit, corporate bonds, and most other private debt is ordinary income, taxed at the same federal rates as your paycheck.1Internal Revenue Service. Topic No. 403 – Interest Received There is no preferential rate the way there is for long-term capital gains or qualified dividends. If you’re in the 24% federal bracket, a dollar of ordinary interest is worth 76 cents after federal tax, before your state takes its share.
Most states with an income tax also tax this interest at their own rates, which run from around 1% to over 13% depending on where you live. The combination is what matters when you compare accounts. A CD paying 5% in a state with a 6% income tax leaves you with less than the same rate paid on a Treasury, because Treasury interest is exempt from state tax entirely.
You owe tax on every dollar of taxable interest, not just the amounts that show up on a form. Banks and brokerages are required to issue Form 1099-INT when they pay you $10 or more, but the reporting threshold has nothing to do with the taxability threshold.2Internal Revenue Service. About Form 1099-INT, Interest Income A few dollars of interest from a small account is legally reportable even without a 1099.1Internal Revenue Service. Topic No. 403 – Interest Received
The 3.8% Net Investment Income Tax
Higher earners owe a surtax on top of ordinary rates. The Net Investment Income Tax adds 3.8% to interest and other investment income once your modified adjusted gross income crosses $200,000 if you file single, $250,000 if married filing jointly, or $125,000 if married filing separately.3Internal Revenue Service. Topic No. 559 – Net Investment Income Tax The 3.8% applies to the smaller of your net investment income or the amount your MAGI exceeds the threshold.
Estates and trusts hit the NIIT at a much lower level, just $16,000 of adjusted gross income for 2026. If your total income is anywhere near these limits, the real tax rate on your interest is higher than the bracket table alone suggests.
When the Tax Is Owed
Interest is taxable the year it is credited, not the year you withdraw it. This is the doctrine of constructive receipt: any amount you could have taken out is treated as income you received, even if you left it in the account.4eCFR. 26 CFR 1.451-2 – Constructive Receipt of Income If your bank posts $200 of interest to your savings in December 2026 and you don’t touch it until March 2027, it belongs on your 2026 return.
There is a narrow exception where a substantial restriction limits your access. A CD with an early-withdrawal penalty that would forfeit part of the interest is one example, and interest that only pays at maturity under a bonus arrangement is another. For ordinary checking and savings, though, the interest is taxable the moment it posts.4eCFR. 26 CFR 1.451-2 – Constructive Receipt of Income
Interest That Escapes Some or All Tax
A handful of categories get preferential treatment, and the differences drive real dollars.
Municipal Bonds
Interest on bonds issued by state and local governments is generally exempt from federal income tax.5Office of the Law Revision Counsel. 26 US Code 103 – Interest on State and Local Bonds Buy a bond issued by your own state and the interest is often exempt from that state’s income tax as well, though the rules vary and not every state extends this benefit.6Municipal Securities Rulemaking Board. Tax Treatment An out-of-state municipal bond usually stays federally exempt but may be fully taxable at the state level.
One important carve-out: interest on certain “private activity” municipal bonds, which fund things like airports or stadiums rather than core government functions, can be pulled back into tax through the alternative minimum tax. If you’re in AMT territory and holding these bonds, the tax-free label doesn’t fully apply.
To compare a muni against a taxable bond, use the tax-equivalent yield: divide the muni’s yield by (1 minus your marginal rate). A 4% muni is worth roughly 6.15% pre-tax to someone in the 35% federal bracket. The higher your bracket, the more the math tilts toward munis.
Treasury Securities
Treasury bills, notes, bonds, and savings bonds are taxable at the federal level but exempt from every state and local income tax.7TreasuryDirect. Tax Information for EE and I Bonds In a high-tax state, that exemption can push the after-tax return above a corporate bond paying a higher stated rate.
Savings Bonds and the Education Exclusion
Series EE and Series I savings bonds add a timing benefit. You can defer reporting the interest until you redeem the bonds or they reach final maturity, up to 30 years out, and most holders take that option.7TreasuryDirect. Tax Information for EE and I Bonds The alternative is to report the accrual each year, but once you pick a method, switching requires following specific IRS procedures.
The interest can be entirely tax-free if the proceeds pay qualified higher education expenses like tuition and fees. The bonds must have been issued after 1989, you must have been at least 24 when they were purchased, and your modified AGI must fall under the annual limits. For 2025, the exclusion phases out above $100,550 for single filers and $158,650 for married filing jointly, with complete phaseout at $114,500 and $179,250. These limits adjust for inflation. Room and board don’t qualify, and the exclusion isn’t available to married taxpayers filing separately.
Zero-Coupon Bonds and Phantom Income
Some interest is taxable before you ever see the cash. Zero-coupon bonds are sold at a deep discount and pay nothing along the way; the interest is the gap between what you paid and the face value at maturity. The IRS calls this original issue discount and requires you to report a slice of it as income every year of the bond’s life, even though no money changes hands until maturity.8Internal Revenue Service. Publication 1212 – Guide to Original Issue Discount (OID) Instruments You get a Form 1099-OID rather than a 1099-INT. Because the tax bill arrives without any cash to pay it, zeros generally sit better inside a tax-deferred account like an IRA than in a taxable brokerage account.
Reporting It on Your Return
Taxable interest goes on line 2b of Form 1040. Tax-exempt interest, including municipal bond interest, goes on line 2a. If your total taxable interest tops $1,500, you also complete Schedule B, itemizing each payer and amount.9Internal Revenue Service. About Schedule B (Form 1040), Interest and Ordinary Dividends
Leaving interest off the return is one of the easiest things for the IRS to catch. Its automated matching program compares every 1099-INT it receives against what taxpayers report; mismatches generate a CP2000 notice proposing additional tax, interest, and often penalties.10Internal Revenue Service. Topic No. 652 – Notice of Underreported Income – CP2000 The accuracy-related penalty for negligence, which covers failing to report income shown on a 1099, is 20% of the resulting underpayment.11Internal Revenue Service. Accuracy-Related Penalty Since the IRS already has the numbers from your bank, the odds of a missing interest line going unnoticed are low.
Interest From Foreign Accounts
Interest earned in a foreign bank account is fully taxable in the United States, and foreign banks generally don’t send 1099s. You have to track it yourself.
Two separate reporting requirements can kick in. If the combined value of your foreign financial accounts tops $10,000 at any point in the year, you file a Report of Foreign Bank and Financial Accounts (FBAR) with FinCEN, due April 15 with an automatic extension to October 15.12Financial Crimes Enforcement Network. Report Foreign Bank and Financial Accounts Separately, if your foreign financial assets exceed $50,000 on the last day of the year (or $75,000 at any point) for single filers, or $100,000 on the last day (or $150,000 at any point) for joint filers, you file Form 8938 with your tax return.13Internal Revenue Service. Do I Need to File Form 8938, Statement of Specified Foreign Financial Assets Two forms, two agencies. Meeting one threshold does not excuse the other.
Penalties are steep. A non-willful FBAR violation can run up to $10,000 per account per year, adjusted for inflation. Willful violations can reach 50% of the account balance or $100,000, whichever is greater. These apply to the failure to file, whether or not any additional tax was owed on the underlying interest.