AMT Lookup Calculator

Check if you owe AMT from AMTI, exemption, and phase-out calculations.

By Konstantin Iakovlev · Updated April 2026 · Source: IRS — Forms, Instructions & Publications

$

Tentative Min Tax

$54,574.00

Additional AMT

$0.00

AMT Calculation

Exemption$90,100.00
AMT Base$209,900.00
Tentative Minimum Tax$54,574.00
Additional AMT Owed$0.00

Use the AMT Lookup Calculator above to calculate your results. Enter your values and see instant results — all calculations run in your browser.

Disclaimer: This calculator is for informational purposes only and does not constitute tax, financial, or legal advice. Results are estimates based on the information you provide and current rates. Always consult a qualified tax professional or financial advisor for advice specific to your situation.

How It Works

The Alternative Minimum Tax runs as a parallel tax system, built to guarantee that high-income earners pay at least a floor amount even after stacking up deductions under the regular rules. An AMT lookup tells you whether you fall into that net and, if you do, roughly how much extra you owe.

Mechanically, the calculation pits two numbers against each other. Your tentative minimum tax, figured under AMT rules with their own adjustments and preference items, is compared to your regular tax liability. When the tentative minimum tax comes out higher, the gap between the two is your AMT. In effect, your tax base is rebuilt from scratch under a stricter rulebook.

Several items behave differently under AMT than under the regular system, and overlooking them throws the result off. State and local taxes (SALT) and incentive stock options (ISOs) are frequent culprits. Because the AMT exemption amounts and phase-out thresholds reset every year, the calculation only holds up if you feed it the current tax year's figures.

Example: Calculating Potential AMT Liability

  1. 1 Input your projected Regular Tax Liability: $100,000. Input your projected Tentative Minimum Tax (after all AMT adjustments and exemptions): $115,000.
  2. 2 The calculator compares these two figures. Since your Tentative Minimum Tax ($115,000) is greater than your Regular Tax Liability ($100,000), you are subject to AMT.
  3. 3 Your AMT liability for the year would be the difference: $115,000 - $100,000 = $15,000.
  4. 4 In this scenario, you would owe an additional $15,000 in tax due to the Alternative Minimum Tax, on top of your regular tax liability. This highlights the importance of proactive tax planning if you anticipate being subject to AMT.

Source: IRS — Forms, Instructions & Publications · Last updated: April 2026

Frequently Asked Questions

How do I know if I owe the alternative minimum tax?
You may owe AMT if you have large state and local tax deductions, exercised incentive stock options, or have significant miscellaneous deductions. The AMT exemption for 2026 is $88,100 for single filers and $137,000 for married filing jointly.
What is the AMT exemption phase-out?
The AMT exemption begins to phase out at $626,350 for single filers and $1,252,700 for married filing jointly in 2026. For every dollar of AMTI above these thresholds, the exemption is reduced by 25 cents.
What tax rate applies to AMT income?
AMT has two rates: 26% on the first $239,100 of AMTI above the exemption (for all filers) and 28% on amounts above that threshold.

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