Yes, municipal bonds are generally tax exempt at the federal level: interest paid on bonds issued by states, cities, counties, and other local government bodies is excluded from your federal gross income.1Office of the Law Revision Counsel. 26 USC 103 – Interest on State and Local Bonds If you buy bonds issued in your home state, that interest is often free from state and local income tax as well. The exemption is real, but it has edges. It covers interest only, not capital gains. Certain categories of municipal bonds don’t qualify. And even genuinely tax-free interest can raise what you pay in Social Security taxes and Medicare premiums.
What the Federal Exemption Actually Covers
The federal exclusion is permanent, not a deferral. You never owe federal income tax on qualifying municipal bond interest, no matter how much of it you collect in a year. That is why the effective borrowing cost is lower for the state and local governments that issue these bonds.
The exemption also reaches bonds issued by U.S. territories, including Puerto Rico, Guam, the U.S. Virgin Islands, American Samoa, and the Northern Mariana Islands.2Internal Revenue Service. TEB Phase III – Applicability of US Income Tax Rules to Territories Territory bonds carry an extra advantage: their interest is exempt from state income tax in every state, not just the issuer’s. For state tax purposes they behave like an in-state bond wherever you live.
State and Local Taxes on Municipal Bond Interest
Federal treatment is uniform. State treatment is not, and it can meaningfully change the after-tax return.
Bonds From Your Own State
Most states exempt interest on bonds issued by that state or its local governments from state income tax. If your city also has a local income tax, in-state bonds are typically exempt there too. This layered result is often called triple tax-free, and it makes in-state bonds most valuable to residents of high-tax jurisdictions.
Bonds From Other States
Interest on out-of-state municipal bonds is generally taxable on your state return at the state’s regular rates, which currently run from roughly 2% to over 13%. If you own a diversified municipal bond fund holding bonds from many states, only the slice of interest attributable to your home state qualifies for the state exemption.
States With No Income Tax
Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, and Wyoming don’t tax personal income. If you live in one of these, the in-state versus out-of-state distinction doesn’t affect you, and you can buy bonds from any issuer without a state-level penalty. The federal exemption is the only tax benefit in play.
What the Exemption Does Not Cover
Capital Gains When You Sell
The exemption applies to interest. If you sell a municipal bond for more than you paid, the profit is a taxable capital gain reportable to both the IRS and your state.3Internal Revenue Service. Topic No. 409, Capital Gains and Losses Hold longer than a year and you get long-term rates. For 2026 those rates are 0% on taxable income up to $49,450 single or $98,900 married filing jointly, 15% up to $545,500 single or $613,700 joint, and 20% above those thresholds.4Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 Sell within a year and the gain is taxed at ordinary income rates.
The Market Discount Rule
Bond investors are often caught out by this one. When you buy a municipal bond on the secondary market below face value, the discount can be taxed as ordinary income at sale or maturity, not at capital gains rates.
The IRS applies a de minimis threshold: market discount counts as zero if it is less than 0.25% of face value multiplied by the number of full years remaining to maturity. A gain within that small window is a capital gain. Cross the threshold and the entire accrued market discount is ordinary income for bonds bought after April 30, 1993.5Internal Revenue Service. Publication 550, Investment Income and Expenses
An example: you buy a bond with 10 years to maturity at $97 per $100 face value. The de minimis threshold is 0.25% × 10 = 2.5%, or $2.50. Your $3 discount exceeds it, so when the bond matures at $100 the $3 gain is ordinary income. Someone in the 35% bracket pays $1.05 per $100 of discount rather than about $0.45 at the 15% long-term rate.
Bonds bought at initial issue with a discount (original issue discount) follow a friendlier rule. If you buy a tax-exempt OID bond at its offering price and hold it to maturity, the OID is treated as additional tax-exempt interest.
Bonds That Don’t Qualify
Not every municipal bond gets the federal exemption. Two categories to watch:
Private activity bonds. When more than 10% of bond proceeds fund private business activities, the IRS classifies the issue as a private activity bond.6Office of the Law Revision Counsel. 26 USC 141 – Private Activity Bond, Qualified Bond Some are “qualified” under the tax code and keep the federal interest exemption, funding things like affordable housing, nonprofit hospitals, student loans, and certain airport improvements. Non-qualifying private activity bonds lose the exemption entirely, and their interest is taxed like corporate bond interest.
Build America Bonds. These taxable municipal bonds were issued in 2009 and 2010 under a federal subsidy program. Their interest is fully taxable to investors at ordinary income rates.7Internal Revenue Service. Frequently Asked Questions on Build America Bonds and Recovery Zone Economic Development Bonds None have been issued since 2010, but many still trade, and you may run into them inside a fund.
The Alternative Minimum Tax
Qualified private activity bond interest is a preference item for the Alternative Minimum Tax and must be added back when running the parallel AMT calculation.8Office of the Law Revision Counsel. 26 USC 57 – Items of Tax Preference If the AMT result exceeds your regular tax, you pay the difference. For 2026 the AMT exemption is $90,100 for single filers and $140,200 for married joint filers, phasing out at $500,000 and $1,000,000 respectively.4Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 Interest from standard governmental municipal bonds, the kind that fund schools, roads, and water systems, is not an AMT preference item.
How Tax-Exempt Interest Can Still Raise Your Tax Bill
This is the part retirees miss most often. Municipal bond interest doesn’t count as taxable income, but it feeds into two federal formulas that use a broader income measure.
Social Security Benefit Taxation
The IRS uses “combined income” to decide how much of your Social Security benefits become taxable. Combined income equals your adjusted gross income plus tax-exempt interest plus half of your Social Security benefits.9Office of the Law Revision Counsel. 26 USC 86 – Social Security and Tier 1 Railroad Retirement Benefits Municipal bond interest goes directly into that middle piece.
The thresholds have not been indexed for inflation:
- Single filers: combined income between $25,000 and $34,000 can make up to 50% of benefits taxable; above $34,000, up to 85%.
- Married filing jointly: the 50% band starts at $32,000; the 85% band starts above $44,000.
Those thresholds are low. A retiree collecting $15,000 in municipal bond interest can easily cross them, leaving the interest tax-free but pulling thousands of dollars of Social Security into taxable income.10Internal Revenue Service. IRS Reminds Taxpayers Their Social Security Benefits May Be Taxable
Medicare Premium Surcharges
Medicare Part B and Part D premiums rise with income through the Income-Related Monthly Adjustment Amount (IRMAA). The Social Security Administration calculates IRMAA using modified adjusted gross income, which explicitly includes tax-exempt interest reported on line 2a of Form 1040.11Social Security Administration. Medicare Income-Related Monthly Adjustment Amount – Life-Changing Event
For 2026, the standard Part B premium is $202.90 per month. Surcharges begin when MAGI exceeds $109,000 for single filers or $218,000 for married joint filers:12Centers for Medicare and Medicaid Services. 2026 Medicare Parts A and B Premiums and Deductibles
- First tier: additional $81.20 per month (total $284.10)
- Second tier: additional $202.90 per month (total $405.80)
- Third tier: additional $324.60 per month (total $527.50)
- Fourth tier: additional $446.30 per month (total $649.20)
- Highest tier (MAGI above $500,000 single or $750,000 joint): additional $487.00 per month (total $689.90)
Municipal bond interest that is invisible on your federal tax bill can still be the income that bumps you into the next IRMAA tier, adding nearly $1,000 per month in premiums for a couple at the top bracket. Run the numbers before assuming tax-exempt is cost-free.
Where the Exemption Really Does Stay Invisible
The 3.8% Net Investment Income Tax applies to gross income from interest. Because municipal bond interest is already excluded from gross income under Section 103, it stays outside the NIIT calculation entirely.13Office of the Law Revision Counsel. 26 USC 1411 – Imposition of Tax1Office of the Law Revision Counsel. 26 USC 103 – Interest on State and Local Bonds The NIIT thresholds are $200,000 for single filers and $250,000 for married joint filers.14Internal Revenue Service. Net Investment Income Tax Capital gains on the sale of municipal bonds, however, are included in net investment income and can trigger the 3.8% surtax.
Comparing a Muni Yield to a Taxable Bond Yield
A 4% municipal bond and a 5% corporate bond aren’t directly comparable because the corporate interest gets taxed. The tax-equivalent yield formula fixes that:
Tax-Equivalent Yield = Tax-Exempt Yield ÷ (1 − Your Marginal Tax Rate)
In the 32% federal bracket, a 4% muni is equivalent to 4% ÷ (1 − 0.32) = 5.88%. A taxable bond would need to yield at least 5.88% to match. In the 37% bracket, the breakeven rises to 6.35%.4Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026
If the bond also qualifies for a state exemption, add your state rate to the federal rate before running the formula. Someone in the 24% federal bracket with a 6% state rate uses a combined 30%: 4% ÷ (1 − 0.30) = 5.71%. The higher your combined bracket, the more the exemption is worth. In the 10% or 12% federal bracket with no state income tax, higher-yielding taxable bonds often win.
Reporting Tax-Exempt Interest
You still have to report the interest even though it isn’t taxed. Your broker or fund company reports tax-exempt municipal interest in Box 8 of Form 1099-INT, with any private activity bond interest that may be subject to AMT reported separately in Box 9.15Internal Revenue Service. Instructions for Forms 1099-INT and 1099-OID The total goes on line 2a of Form 1040 as an information-reporting item; it doesn’t add to taxable income or change your federal tax.16Internal Revenue Service. Topic No. 403, Interest Received If you bought a bond between coupon dates and paid accrued interest to the seller, subtract that amount from the interest shown on the 1099, since it belongs to the previous owner.17Internal Revenue Service. Instructions for Schedule B (Form 1040)