Free 2026 AMT calculator. Estimate Alternative Minimum Tax using AMTI, exemption phaseouts, and tentative minimum tax so you can see whether AMT exceeds regular federal tax.
The Alternative Minimum Tax (AMT) Calculator estimates whether your tentative minimum tax may exceed your regular federal tax for the 2026 tax year. AMT is a parallel tax system that recalculates taxable income after adding back certain deductions or preference items, then applies a separate exemption and a two-rate structure.
Common AMT triggers include large SALT addbacks, incentive stock option exercises, and other preference items that are treated differently under Form 6251. This page is meant to help you estimate the size of the exposure before filing, not to replace a full AMT return preparation.
For 2026, the AMT exemption is $90,100 for single and head-of-household filers, $140,200 for married filing jointly, and $70,100 for married filing separately. The exemption begins phasing out at $500,000 for unmarried and MFS filers and $1,000,000 for joint returns.
AMT can catch high-income taxpayers by surprise, especially those exercising ISO stock options, claiming large SALT deductions, or earning income from private activity bonds. This calculator flags AMT exposure before filing so you can plan accordingly. Early detection gives you the opportunity to adjust your year-end tax strategy and potentially reduce or eliminate the additional liability.
AMTI = Taxable Income + AMT Preference Items (SALT, ISO spread, etc.) AMT Exemption (2026): $90,100 single / HoH, $140,200 MFJ, $70,100 MFS Exemption Phase-Out Start: $500,000 single / HoH / MFS, $1,000,000 MFJ Exemption reduced by 25¢ per $1 over phase-out start AMT Base = AMTI – Exemption Tentative Minimum Tax = 26% on first $244,500 ($122,250 MFS) + 28% on excess AMT Owed = Max(0, Tentative Minimum Tax – Regular Tax)
Result: AMTI: $365,000 | AMT owed: $10,082
Taxable income $300,000 + $15,000 SALT addback + $50,000 ISO spread = $365,000 AMTI. The 2026 single exemption is $90,100, so AMT base is $274,900. Tentative minimum tax is $244,500 × 26% + $30,400 × 28% = about $72,082. Compared with regular tax of $62,000, the estimated AMT owed is about $10,082.
The AMT runs alongside the regular income tax and you pay whichever calculation is higher. It broadens the income base by reversing selected deductions and preference items, then applies only two rates: 26% and 28%. The exemption cushions the calculation for many taxpayers, but that exemption shrinks as AMTI rises through the phaseout range.
Incentive stock option exercises remain one of the most common reasons individual taxpayers run into AMT. The bargain element between the strike price and fair market value is not taxed as regular wage income on exercise, but it is an AMT preference item. That is why this page keeps the ISO spread separate from other adjustments.
Real Form 6251 preparation can include additional adjustments for depreciation, passive losses, private activity bond interest, net operating loss differences, and AMT credit carryforwards. Use this page to estimate exposure and compare scenarios, then confirm the final numbers with the actual IRS worksheets or a tax professional.
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This page starts with taxable income and adds the AMT preference items collected on the form, such as SALT addback, ISO bargain element, and other adjustments, to estimate alternative minimum taxable income (AMTI). It then applies the 2026 AMT exemption and phaseout rules, computes tentative minimum tax at 26% and 28%, and compares that result with the regular tax entered by the user.
This is a simplified individual AMT worksheet, not a full Form 6251 engine. It does not model every AMT adjustment, every preference item, or the AMT credit carryforward calculation from Form 8801.
The AMT is a parallel tax system that limits certain deductions and adds back preference items to ensure high-income taxpayers pay at least a minimum amount of tax. It applies two rates (26% and 28%) to a broader income base. You owe AMT only when the tentative minimum tax exceeds your regular income tax.
Common preference items include: state and local tax (SALT) deductions, the bargain element from exercising incentive stock options (ISOs), tax-exempt interest from private activity bonds, accelerated depreciation differences, and certain passive activity losses. These items are added back to regular taxable income to calculate AMTI.
For 2026, the AMT exemption is $90,100 for single and head-of-household filers, $140,200 for married filing jointly, and $70,100 for married filing separately. The exemption begins phasing out at $500,000 for unmarried filers and $1,000,000 for joint returns.
Taxpayers most likely to owe AMT include those who exercise large amounts of ISOs, claim large SALT deductions, have significant private activity bond income, or have high income with many deductions. The risk is highest for income between $200,000 and $500,000.
Yes, if your AMT was caused by timing differences (like ISO exercises that create a temporary AMT adjustment), you can claim an AMT credit in future years when your regular tax exceeds the tentative minimum tax. This credit helps recover AMT paid on timing items.
The AMT exemption is reduced by 25 cents for every dollar of AMTI above the phaseout threshold. For 2026, that means complete phaseout at $680,200 for single or head-of-household filers, $640,200 for married filing separately, and $1,280,400 for married filing jointly.