AMT Calculator 2026
Calculate your 2026 Alternative Minimum Tax (AMT) using OBBB-updated exemption amounts and phaseout thresholds. Enter your regular taxable income and all AMT preference items — SALT add-back, private activity bond interest, ISO exercise gains, depreciation differences, and more — to find your exact AMT liability per IRS Form 6251. Free, private, runs entirely in your browser.
What Is the Alternative Minimum Tax and Who Owes It in 2026?
The Alternative Minimum Tax (AMT) is a parallel federal income tax system designed to ensure that high-income taxpayers pay a minimum level of tax, even when using legal deductions and tax preference items. Established by Congress in 1969, the AMT recomputes your tax liability after adding back specific deductions and income items that are excluded under the regular tax system. If the resulting tentative minimum tax exceeds your regular income tax, you pay the difference as AMT. For 2026, the IRS (Form 6251) and OBBB provisions set new inflation-adjusted exemptions: $88,100 for Single filers, $137,000 for Married Filing Jointly, and $68,500 for Married Filing Separately. The phaseout begins at $609,350 for Single and $1,218,700 for MFJ, meaning very-high-income households see their exemptions gradually reduced.
2026 AMT Preference Items and How They Add to AMTI
Your AMT Income (AMTI) starts with your regular taxable income and then adds back specific preference items that reduce regular tax but are disallowed under AMT. Understanding each item helps you plan to minimize exposure:
- State and Local Tax (SALT) Add-Back: The SALT deduction (capped at $10,000 under TCJA for regular tax) is entirely disallowed under AMT. If you deducted $10,000 of SALT, the full $10,000 is added back to compute AMTI. This is the most common AMT trigger for upper-middle-income households.
- Private Activity Bond Interest: Interest from certain municipal bonds issued to finance private activities (e.g., airport bonds, housing bonds) is tax-exempt for regular income tax purposes but counted as a preference item under AMT. Check your 1099-INT box 9 or broker statement.
- ISO Exercise Bargain Element: When you exercise Incentive Stock Options (ISOs) but do not sell the shares in the same year, the spread between the fair market value and the exercise price is not taxed for regular purposes — but it is fully included in AMTI. This is a major AMT trigger for tech employees with large ISO grants.
- Accelerated Depreciation: The difference between MACRS depreciation taken for regular tax and straight-line depreciation for AMT purposes is added back. Businesses with significant depreciable assets may face AMT from this item.
- Home Equity Loan Interest: Interest on home equity debt not used to buy, build, or substantially improve your home is not deductible under AMT (though it was reinstated for regular tax under OBBB for qualifying uses). If you took this deduction on Schedule A, it must be added back.
According to irs.gov (Form 6251), these items collectively form AMTI, from which your exemption is subtracted to arrive at the AMT base. Based on IRS statistics, approximately 200,000–400,000 households pay AMT annually post-TCJA, primarily those with high ISO exercises or large SALT deductions in high-tax states. Sources: irs.gov (Form 6251), OBBB P.L. 119-21. Last updated: May 2026.
How the AMT Exemption Phaseout Works in 2026
The AMT exemption is not a flat amount for everyone — it phases out for higher-income taxpayers at a rate of $0.25 for every $1 of AMTI above the phaseout threshold. For 2026, the phaseout begins at $609,350 (Single) and $1,218,700 (MFJ). The exemption is fully phased out when AMTI reaches the threshold plus four times the exemption amount.
For example, a Single filer with $88,100 in exemption sees it begin to phase out at $609,350 AMTI. The exemption is fully eliminated when AMTI exceeds $609,350 + (4 × $88,100) = $961,750. Between those income levels, the effective marginal AMT rate is not just 26%/28% — it rises to 32.5%–35% due to the phaseout clawback. This calculator accurately computes the phaseout reduction and shows you the exact reduced exemption amount so there are no surprises.
AMT Rates and When You Enter the 28% Bracket
The AMT applies two tax rates to the AMT base (AMTI minus exemption). For 2026, the rate structure is: 26% on the first $248,300 of AMT base (or $124,150 for Married Filing Separately), and 28% on all amounts above that threshold. This is a significant difference from the regular tax system's graduated brackets — the AMT uses only two rates with a much higher floor rate.
Long-term capital gains and qualified dividends receive preferential treatment even under the AMT: they are generally subject to the same 0%/15%/20% rates as under the regular tax (not the 26%/28% AMT rates). This calculator applies the standard 26%/28% rate structure to the full AMT base as reported on Form 6251, which is appropriate for most taxpayers with ordinary income subject to AMT. If you have significant capital gains, the qualified dividends/capital gains worksheet may reduce your actual AMT — consult Form 6251 instructions or a tax professional for that advanced computation.
Frequently Asked Questions
What is the AMT exemption for 2026?
For 2026 under OBBB-updated IRS parameters, the AMT exemption amounts are: $88,100 for Single filers, $137,000 for Married Filing Jointly, $68,500 for Married Filing Separately, and $88,100 for Head of Household. These exemptions phase out at $0.25 per $1 of AMTI above $609,350 (Single) and $1,218,700 (MFJ). The exemption ensures that moderate-income taxpayers are not subject to AMT even with some preference items.
What triggers the AMT in 2026?
The most common AMT triggers in 2026 are: (1) exercising Incentive Stock Options (ISOs) without selling the stock in the same year — the bargain element is a preference item; (2) large SALT deductions, since the $10,000 SALT cap allowed for regular tax is fully added back for AMT; (3) private activity bond interest from certain municipal bonds; (4) accelerated depreciation differences; and (5) other deductions not allowed under AMT such as home equity interest on non-improvement debt. High-income households in high-tax states with ISOs face the highest AMT risk.
How is the AMT calculated step by step?
The AMT calculation follows these steps per IRS Form 6251: (1) Start with regular taxable income from Form 1040 line 15; (2) Add back all AMT preference items (SALT, ISO bargain element, private activity bond interest, depreciation differences, home equity interest, etc.) to arrive at AMTI; (3) Subtract the AMT exemption (reduced by the phaseout if AMTI exceeds the threshold); (4) Apply 26% to the first $248,300 and 28% above that — this is the tentative minimum tax; (5) Subtract your regular tax liability; (6) If the result is positive, that is your AMT owed.
What are the AMT tax rates for 2026?
The 2026 AMT uses two rates: 26% on the first $248,300 of AMT base (the amount after subtracting the exemption from AMTI), and 28% on any AMT base above $248,300. For Married Filing Separately, the 26% bracket applies to the first $124,150. Note that long-term capital gains and qualified dividends are NOT taxed at the 26%/28% AMT rates — they retain the preferential 0%/15%/20% rates even under AMT calculations.
Can I get a credit for AMT paid in prior years?
Yes. When you pay AMT due to deferral items (such as ISO exercises), the amount paid generates a Minimum Tax Credit (MTC) that can offset regular tax liability in future years when your regular tax exceeds your tentative minimum tax. The credit is claimed on Form 8801. This is particularly important for ISO exercises: if you exercised ISOs and paid AMT, you may recover that tax in later years when you sell the stock (triggering regular capital gains tax) or when your circumstances change. This calculator does not compute the MTC carryforward — consult a tax professional.
Does OBBB (One Big Beautiful Bill) change the AMT for 2026?
Yes. OBBB (P.L. 119-21) extended and inflation-adjusted the TCJA AMT parameters that were set to expire after 2025. Key changes include higher exemption amounts ($88,100 Single / $137,000 MFJ vs. the pre-TCJA amounts of ~$54,300/$84,500), significantly elevated phaseout thresholds, and maintenance of the SALT cap that creates AMT add-back exposure. Without OBBB, the AMT exemptions would have reverted to much lower pre-2018 levels, and millions more taxpayers would have owed AMT. The OBBB provisions ensure the AMT continues to affect primarily very-high-income households.