ISO AMT Calculator 2026

Estimate Alternative Minimum Tax when exercising Incentive Stock Options — find your AMT crossover point

ISO exercise details

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ISO bargain element: $100,000(5,000 × ($25$5))
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Excluding the ISO exercise income

$

e.g. private activity bond interest, certain depreciation adjustments

%

Used to estimate SALT deduction added back for AMTI

2026 OBBBA change: The AMT exemption phaseout rate doubled from 25¢ to 50¢ per dollar above the threshold. This significantly increases AMT exposure for high earners exercising ISOs.

AMT calculation

AMT owed (Form 6251)
$13,254
Total tax: $45,188 (regular $31,934 + AMT $13,254)
AMT crossover point
2,451shares
Max shares you can exercise without triggering AMT (bargain element: $49,020)
Regular tax vs. AMT calculation
W-2 salary$180,000
Standard deduction (Single)$16,100
Regular taxable income$163,900
Regular tax (2026 brackets)$31,934
ISO bargain element$100,000
Other AMT preferences$0
SALT deduction added back$0
AMTI (Alternative Minimum Taxable Income)$263,900
AMT exemption (Single)$90,100
Phaseout reduction (50¢ per $1 above $500,000)$0
AMT exemption after phaseout$90,100
AMT taxable income$173,800
Tentative minimum tax (26% up to $244,500 + 28% above)$45,188
AMT owed (TMT − regular tax)$13,254
Total tax (regular + AMT)$45,188
AMT credit recovery: The $13,254 in AMT generates a credit on Form 8801 that carries forward indefinitely. In future years when your regular tax exceeds AMT, you can use this credit to reduce your regular tax bill.

• 2026 AMT exemption: $90,100 (Single) / $140,200 (MFJ)

• OBBBA phaseout: 50¢ per dollar above $500,000 (Single) / $1,000,000 (MFJ)

• AMT rates: 26% on first $244,500, 28% above

• Assumes standard deduction (itemizing may change results)

• SALT deduction estimated from state tax rate on salary

What is How to Use the ISO AMT Calculator?

When you exercise Incentive Stock Options (ISOs) and hold the shares, the bargain element (FMV minus strike price) is added to your Alternative Minimum Taxable Income. This can trigger AMT — a parallel tax system that may result in a significant tax bill on paper gains.

How to Use

  1. Enter the number of ISO shares you plan to exercise
  2. Input your strike price and the current FMV per share
  3. Enter your annual W-2 salary (excluding the ISO exercise)
  4. Select your filing status
  5. Add any other AMT preference items if applicable
  6. Review whether AMT applies and how much you would owe

Why Use This Tool?

Find your AMT crossover point — the maximum shares you can exercise without triggering AMT
Understand how the 2026 OBBBA phaseout changes affect your AMT exposure
Plan multi-year exercise strategies to minimize AMT
See the AMT credit you can recover in future years

Tips & Best Practices

  • The 2026 OBBBA accelerated AMT exemption phaseout to 50 cents per dollar (up from 25 cents), increasing AMT exposure for high earners
  • AMT paid on ISO exercises generates a credit (Form 8801) that you can recover when your regular tax exceeds AMT in future years
  • Exercise and sell in the same year (disqualifying disposition) eliminates the AMT preference item but taxes the spread as ordinary income
  • Coordinate ISO exercises with high-income years when your regular tax already exceeds AMT
  • Consider exercising early in the year to give yourself time to sell before year-end if AMT is too high

Frequently Asked Questions

When does exercising ISOs trigger AMT?

AMT is triggered when you exercise ISOs and hold the shares. The bargain element (FMV at exercise minus strike price times shares) is added to your AMT income. If your tentative minimum tax exceeds your regular tax, you owe AMT on the difference.

What is the AMT crossover point?

The AMT crossover point is the maximum ISO bargain element you can exercise in a year without triggering AMT. It equals the available AMT headroom divided by the effective AMT rate on the bargain element.

Can I recover AMT paid on ISO exercises?

Yes. AMT paid due to ISO exercises generates an AMT credit (Form 8801) that carries forward indefinitely. In future years when your regular tax exceeds AMT, you can use the credit to reduce your regular tax.

What are the 2026 AMT exemption amounts?

For 2026, the AMT exemption is $90,100 for single filers and $140,200 for married filing jointly. The exemption phases out at higher incomes under OBBBA rules.

How do I avoid AMT when exercising ISOs?

Exercise only enough shares to stay below your AMT crossover point, coordinate exercises with high-income years, or exercise and sell in the same year (disqualifying disposition) which eliminates the AMT preference item.

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