⚖️ AMT Calculator 2026
Alternative Minimum Tax Estimator with Official IRS Rates
📊 Understanding Alternative Minimum Tax
The AMT calculator 2026 helps you determine if you owe Alternative Minimum Tax—a parallel tax system designed to ensure high-income taxpayers pay at least a minimum amount of tax. You calculate both your regular tax AND your AMT, then pay whichever is higher. The AMT disallows certain deductions (like state/local taxes over $10K) and adds back "preference items" like ISO exercise gains. In 2026, exemptions range from $66,650 to $133,300 depending on filing status, with rates of 26% and 28%. This calculator is essential for tech employees exercising stock options, high-income taxpayers in high-tax states, and anyone claiming large itemized deductions. Know your AMT liability before it surprises you at tax time!
📝 How to Use the AMT Calculator
- Select your filing status: Choose Single, Married Filing Jointly, Married Filing Separately, or Head of Household. This determines your exemption amount and phaseout thresholds.
- Enter regular taxable income: Input your taxable income from Form 1040 (Line 15). This is your starting point before AMT adjustments.
- Add AMT adjustments: Enter amounts for SALT deductions (added back for AMT), incentive stock option exercise spreads, private activity bond interest, and other AMT preferences.
- Enter your regular tax liability: Input your regular tax from Form 1040 (before credits). The calculator compares this to your tentative AMT.
- Click "Calculate AMT": View whether AMT applies, how much additional tax you owe, and a complete breakdown of your AMTI and exemption calculations.
📐 AMT Formula & Calculation Method
Alternative Minimum Taxable Income (AMTI)
Start with your regular taxable income from Form 1040, then add back items disallowed under AMT: SALT deductions, ISO exercise spreads, private activity bond interest, and other preferences from Form 6251.
Exemption Phaseout Calculation
The exemption reduces by 25 cents for every dollar of AMTI above the threshold. For Single filers in 2026, phaseout begins at $609,350. The exemption can be reduced to zero for very high incomes.
Tentative Minimum Tax (TMT)
Apply 26% to AMT base up to $220,700, then 28% on amounts above. This is your tentative minimum tax before comparing to regular tax.
AMT Owed
You only owe AMT if your tentative minimum tax exceeds your regular tax. The difference is your additional AMT liability added to your regular tax.
📊 AMT Examples
Example 1: High-Income Professional (No AMT)
Scenario: Sarah is a single attorney with $200,000 taxable income and $12,000 SALT. No ISOs or other preferences.
Inputs: Income: $200,000 | SALT: $12,000 | Regular Tax: $40,000
- AMTI: $200,000 + $12,000 = $212,000
- Exemption: $85,700 (no phaseout—below threshold)
- AMT Base: $212,000 − $85,700 = $126,300
- Tentative AMT: $126,300 × 26% = $32,838
Result: Regular tax ($40,000) > TMT ($32,838) = NO AMT OWED ✓
Example 2: Tech Employee with ISO Exercise
Scenario: Mike is single and exercised ISOs with a $150,000 bargain element. Regular income $180,000.
Inputs: Income: $180,000 | SALT: $10,000 | ISO Spread: $150,000 | Regular Tax: $35,000
- AMTI: $180,000 + $10,000 + $150,000 = $340,000
- Exemption: $85,700 (no phaseout yet)
- AMT Base: $340,000 − $85,700 = $254,300
- TMT: ($220,700 × 26%) + ($33,600 × 28%) = $57,382 + $9,408 = $66,790
Result: TMT ($66,790) > Regular ($35,000) = AMT OWED: $31,790
Example 3: High-Income MFJ with Phaseout
Scenario: John & Mary file jointly with $800,000 income, $25,000 SALT, and $50,000 ISO spread.
Inputs: Income: $800,000 | SALT: $25,000 | ISO: $50,000 | Regular Tax: $200,000
- AMTI: $800,000 + $25,000 + $50,000 = $875,000
- Base Exemption: $133,300
- Phaseout: ($875,000 − $609,350) × 25% = $66,413 (capped at $133,300)
- Net Exemption: $133,300 − $66,413 = $66,887
- AMT Base: $875,000 − $66,887 = $808,113
- TMT: ($220,700 × 26%) + ($587,413 × 28%) = $221,858
Result: TMT ($221,858) > Regular ($200,000) = AMT OWED: $21,858
📊 2026 AMT Exemptions & Thresholds Reference Table
| Filing Status | AMT Exemption | Phaseout Begins | 28% Rate Above | Exemption Eliminated At |
|---|---|---|---|---|
| Single | $85,700 | $609,350 | $220,700 | $952,150 |
| Married Filing Jointly | $133,300 | $1,218,700 | $220,700 | $1,751,900 |
| Married Filing Separately | $66,650 | $609,350 | $110,350 | $875,950 |
| Head of Household | $85,700 | $609,350 | $220,700 | $952,150 |
Source: IRS Topic 556 - Alternative Minimum Tax
💡 Important Tips for AMT Planning
- ISO Timing: Spread ISO exercises across multiple tax years to stay below AMT thresholds. Consider exercising early in the year to allow time for 83(b) elections or same-year sales.
- SALT Impact: The $10,000 SALT cap already limits AMT exposure for most taxpayers. If you itemize over $10K, the excess doesn't add more AMT impact.
- AMT Credit: AMT paid on timing differences (like ISOs) may generate an AMT credit (Form 8801) you can use in future years when regular tax exceeds TMT.
- Year-End Planning: If you're near AMT thresholds, consider accelerating income or deferring deductions to optimize between regular and AMT systems.
- Form 6251: Use IRS Form 6251 for official AMT calculations. This calculator provides estimates—consult a tax professional for complex situations.
- Capital Gains: Long-term capital gains are taxed at preferential rates under BOTH regular and AMT systems—they don't trigger AMT by themselves.
❓ Frequently Asked Questions
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📚 Official IRS Resources
- IRS Topic 556 - Alternative Minimum Tax
- Form 6251 (AMT for Individuals)
- Form 8801 (Credit for Prior Year AMT)
- IRS Publication 17 - Your Federal Income Tax
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Last Updated: January 2026 | Tax Year 2026