AMT calculator 2026: exemption, phaseout, 26/28% rates
Add up the preference items and see whether the parallel tax system actually applies to you this year.
Updated November 4, 2026 Sources and methodology
How AMT is computed, line by line
- AMTI = taxable income + disallowed items. The standard deduction is disallowed, so it is added back; the ISO bargain element is added in full.
- Exemption = $90,100 (single) or $140,200 (joint), reduced by 50% of AMTI above the phaseout threshold, never below zero.
- Tentative minimum tax = 26% of the AMT base up to $244,500, then 28%. Long-term capital gains keep their preferential rates inside the AMT calculation.
- AMT owed = tentative minimum tax − regular tax, if positive.
2026 figures used here
| Parameter | Single | Joint |
|---|---|---|
| Exemption | $90,100 | $140,200 |
| Phaseout starts | $500,000 | $1,000,000 |
| Exemption fully gone | $680,200 | $1,280,400 |
| 28% rate above | $244,500 | $244,500 |
Why 28% is not the real top rate
In the phaseout band each extra dollar of AMTI both increases the base and eliminates 50 cents of exemption, so the marginal cost is 28% × 1.5 = 42% on ordinary preference income, which is more than the top regular rate. That is the reason a large ISO exercise in a single year is so expensive and why spreading exercises across years is the standard planning response. Pair this page with the ISO crossover calculator to find the exercise size that stays under the line.
Frequently asked
What are the 2026 AMT exemption amounts?
$90,100 for single filers, $140,200 for married filing jointly, $70,100 for married filing separately, and $31,400 for estates and trusts. The exemption phases out at 50 cents per dollar of AMTI above $500,000 (single or separate) or $1,000,000 (joint).
What triggers AMT in practice?
For most employees it is the ISO bargain element. Other common items are large state and local tax deductions, private activity bond interest, and certain depreciation adjustments. The standard deduction is not allowed for AMT, so it is added back automatically here.
Why do the phaseout thresholds look low?
Congress made the higher AMT exemptions permanent in 2025 but left the phaseout thresholds at $500,000 and $1,000,000, without indexing them before 2027. Above those levels the effective AMT rate on an extra dollar of preference income rises to roughly 35%.
Sources. IRS Rev. Proc. 2025-32, sections 4.10 and 4.11 (2026 AMT exemption, phaseout and 28% threshold) and section 4.03 (capital-gain breakpoints). Statutory basis: Code sections 55, 56 and 57. Estimates exclude credits, foreign tax items and multi-year minimum tax credit carryforwards.