Are Municipal Bonds Taxable? Federal, State, and AMT Rules

Municipal bonds are partly taxable. The interest you earn on a qualifying state or local government bond is exempt from federal income tax, and often from state and local tax if you live in the state that issued it. But that exemption is narrower than it sounds: profits from selling a bond, interest from certain private activity bonds, and the way tax-exempt interest feeds into other calculations can all produce a tax bill.

Federal Tax on the Interest

Federal law excludes interest on state and local government bonds from your gross income, which is why municipal bonds appeal to investors in higher brackets.¹ The interest simply does not enter the income figure used to calculate your federal tax.

Three categories of bonds fall outside the exemption. Interest is taxable if the bond is a non-qualified private activity bond (one that funds private projects without meeting specific federal requirements), an arbitrage bond (one where the issuer reinvests proceeds in higher-yielding taxable securities), or a bond that fails registration and other issuance requirements.¹ When interest falls outside the exemption, it is taxed at ordinary federal rates, which run from 10% to 37% for the 2026 tax year.²

Tax-exempt municipal bond interest also stays out of the 3.8% Net Investment Income Tax that applies to higher-income taxpayers. Because the interest is already excluded from gross income, it does not count as net investment income for that surtax.³

State and Local Tax on the Interest

Most states exempt municipal bond interest only when you live in the state that issued the bond. A California resident holding a bond issued by a California city typically owes no state income tax on the interest. Combined with the federal exemption and any local exemption, this can produce what investors call “triple-tax-free” income.

Bonds issued by another state usually generate interest that your home state will tax. State income tax rates vary widely, and higher-bracket rates run roughly from 1% to over 13%, so the in-state advantage can matter a lot. If you live in a state with no personal income tax, this distinction is moot.

Bonds From U.S. Territories

Bonds issued by the governments of Puerto Rico, Guam, and the U.S. Virgin Islands are exempt from federal, state, and local taxes no matter where you live in the United States.⁴ Territory bonds function like in-state bonds for every U.S. investor.

Capital Gains When You Sell

The federal exemption covers interest only. If you sell a municipal bond before maturity for more than you paid, the profit is a capital gain and is fully taxable. Hold the bond for a year or less and the gain is taxed at your ordinary income rate. Hold it more than a year and the long-term capital gains rates of 0%, 15%, or 20% apply, depending on your taxable income.⁵ Most states tax capital gains as well.

Selling at a loss works the other way. A capital loss can offset other capital gains and reduce your ordinary income by up to $3,000 per year, with unused losses carrying forward.⁵

Market Discount Bonds

Buying a bond on the secondary market at less than face value creates a market discount. A small discount gets favorable treatment. If it falls within the “de minimis” threshold (one-quarter of 1% of face value multiplied by the number of full years remaining to maturity), any price appreciation at maturity or sale is treated as a capital gain.

If the discount exceeds that threshold, the IRS treats the accrued market discount as ordinary income when you sell or redeem the bond, not as a capital gain and not as tax-exempt interest.⁶ Say you buy a bond with 10 years to maturity at $96 per $100 of face value. The de minimis threshold is 2.5% ($0.25 × 10 years). Your $4 discount exceeds that, so the accrued market discount portion of your gain at maturity would be taxed as ordinary income. This catches secondary-market buyers who assume all appreciation on a municipal bond is tax-free.

Wash Sale Rule

If you sell a municipal bond at a loss and buy a substantially identical bond within 30 days before or after the sale, the wash sale rule disallows the loss deduction.⁷ The disallowed loss gets added to your cost basis in the replacement bond, so it is deferred rather than permanently lost. To harvest a loss cleanly, make sure the replacement bond differs meaningfully in issuer, coupon rate, or maturity date.

The Alternative Minimum Tax

Most municipal bond interest is exempt from the Alternative Minimum Tax, but interest from private activity bonds is not. These bonds fund projects that primarily benefit private entities, such as airport terminals leased to airlines, housing developments, or nonprofit hospital expansions. When the interest on these bonds qualifies as a tax preference item, you must add it back when calculating whether you owe AMT.⁸

The AMT runs as a parallel calculation. You figure your tax under both systems and pay whichever is higher. For 2026, the AMT exemption is $90,100 for single filers and $140,200 for married couples filing jointly. It begins to phase out at $500,000 for single filers and $1,000,000 for joint filers.² Well below those thresholds, private activity bond interest is unlikely to trigger extra tax. Investors worried about exposure can look for bonds labeled “AMT-free” in their offering documents.

Effect on Social Security Benefits

Municipal bond interest is not taxed directly, but it can cause more of your Social Security benefits to be taxed. Federal law requires you to include tax-exempt interest when calculating the “provisional income” figure the IRS uses to decide how much of your Social Security is taxable.⁹ The calculation adds your adjusted gross income, half your Social Security benefits, and all tax-exempt interest.

The thresholds that trigger taxation of Social Security benefits are:

$25,000 (individual) or $32,000 (joint): above these amounts, up to 50% of benefits become taxable.⁹
$34,000 (individual) or $44,000 (joint): above these amounts, up to 85% of benefits become taxable.⁹

These thresholds are not adjusted for inflation, so they reach more retirees over time. A large municipal bond portfolio can push provisional income past these lines even though the interest itself stays untaxed.

Effect on Medicare Premiums

Tax-exempt interest also feeds into Medicare premium calculations. The Social Security Administration sets your Medicare Part B and Part D premiums using modified adjusted gross income, defined as your adjusted gross income plus tax-exempt interest.¹⁰ If your MAGI exceeds certain thresholds, you pay an Income-Related Monthly Adjustment Amount (IRMAA) on top of the standard premium.

For 2026, the standard Part B premium is $202.90 per month. IRMAA surcharges for Part B begin when MAGI exceeds $109,000 (individual) or $218,000 (married filing jointly) and rise in tiers:¹¹

$109,001–$137,000 (individual): $81.20 per month surcharge on Part B
$137,001–$171,000: $202.90 surcharge
$171,001–$205,000: $324.60 surcharge
$205,001–$499,999: $446.30 surcharge
$500,000 and above: $487.00 surcharge

Similar surcharges apply to Part D premiums, running from $14.50 to $91.00 per month at the same income tiers.¹¹ SSA uses tax returns from two years earlier (your 2024 return for 2026 premiums), so a big interest year takes two years to show up in your premium.

Reporting Tax-Exempt Interest

Even when no federal tax is owed, you still have to report the interest. Your brokerage sends a Form 1099-INT showing tax-exempt interest in Box 8, and you report that total on Line 2a of Form 1040.¹² If you hold a tax-exempt bond with original issue discount, the OID amount appears in Box 11 of Form 1099-OID and also goes on Line 2a.

When you buy a municipal bond between interest payment dates, you usually pay the seller for interest that has accrued since the last payment. That accrued interest is taxable to the seller, not to you. If your Form 1099 includes it, subtract it using the nominee reporting instructions on Schedule B and label the adjustment “Accrued Interest.”¹³

Reporting is mandatory because the IRS uses tax-exempt interest to figure provisional income for Social Security and to check AMT liability. Leaving it off can prompt an automated inquiry. Keep your 1099-INT and 1099-OID records for at least three years after filing.¹⁴

1
Office of the Law Revision Counsel. 26 USC 103 – Interest on State and Local Bonds
2
Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026
3
Internal Revenue Service. Topic No. 559, Net Investment Income Tax
4
Office of the Law Revision Counsel. 48 USC 745 – Tax Exempt Bonds
5
Internal Revenue Service. Topic No. 409, Capital Gains and Losses
6
Office of the Law Revision Counsel. 26 USC 1276 – Disposition Gain Representing Accrued Market Discount Treated as Ordinary Income
7
Office of the Law Revision Counsel. 26 USC 1091 – Loss From Wash Sales of Stock or Securities
8
Office of the Law Revision Counsel. 26 USC 57 – Items of Tax Preference
9
Office of the Law Revision Counsel. 26 USC 86 – Social Security and Tier 1 Railroad Retirement Benefits
10
Social Security Administration. Premiums: Rules for Higher-Income Beneficiaries
11
Centers for Medicare & Medicaid Services. 2026 Medicare Parts A and B Premiums and Deductibles
12
Internal Revenue Service. Instructions for Form 1040
13
Internal Revenue Service. Instructions for Schedule B (Form 1040)
14
Internal Revenue Service. How Long Should I Keep Records?