# How much AMT will I owe?

Estimates the 2026 alternative minimum tax: AMT income, the exemption and its phase-out, the 26% and 28% tentative minimum tax, and the AMT owed over the regular tax, with incentive stock options.

- Page: https://www.acalculator.org/finance/amt-calculator
- JSON spec: https://www.acalculator.org/finance/amt-calculator.json
- Version: 5e0980863f9a

## Default answer

Example with the default inputs (Filing status Single, Income (AGI) $200,000.00, State and local taxes deducted $10,000.00, Other itemized deductions $5,000.00, Incentive stock option spread $100,000.00, Other AMT adjustments $0.00): With $300,000.00 of AMT income, your tentative minimum tax is $54,574.00 against $36,734.00 of regular tax, so you owe $17,840.00 of AMT.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| status | Filing status | Your federal filing status. Married filing separately is not covered. |
| income | Income (AGI) | Your adjusted gross income for the year (Form 1040 line 11). |
| salt | State and local taxes deducted | The state and local income, sales, and property taxes you paid; the 2026 limit is applied for you. |
| item | Other itemized deductions | Mortgage interest, gifts to charity, and medical costs over 7.5% of AGI. |
| iso | Incentive stock option spread | For ISOs you exercised and kept at year end: (value at exercise − price paid) × shares. |
| adj | Other AMT adjustments | Tax-exempt interest from private activity bonds and other Form 6251 adjustments, as a positive number. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| amt | Alternative minimum tax | Form 6251 line 11: tentative minimum tax over the regular tax, or 0. |
| tmt | Tentative minimum tax | 26% and 28% of the AMT base. |
| regular | Regular income tax | Form 1040 line 16 tax, with the larger of the standard and itemized deduction. |
| total | Total income tax | Regular tax plus AMT. |
| amti | AMT income (AMTI) | Taxable income with the AMT add-backs and adjustments. |
| exemption | AMT exemption | The exemption after the 50% phase-out over the threshold. |
| base | AMT base | AMTI minus the exemption. |

## Method

AMTI = AGI − other itemized deductions (when you itemize; the standard deduction and state and local taxes are not allowed) + ISO spread + other adjustments. Exemption = $90,100 single or head of household, $140,200 jointly, less 50% of AMTI over $500,000 ($1,000,000 jointly), not below 0. Base = AMTI − exemption. Tentative minimum tax = 26% × base, or 28% × base − $4,890 above $244,500. AMT = tentative minimum tax − regular tax, if positive.

## Assumptions

- An estimate for tax year 2026 (IRS Rev. Proc. 2025-32 and Form 6251), not tax advice.
- All income is ordinary income: qualified dividends and long-term gains, which keep their 0%, 15%, and 20% rates under AMT, are not included. No credits, no AMT foreign tax credit, no minimum tax credit from earlier years.
- Married filing separately is not covered: its phase-out has an extra AMTI add-on.
- Other itemized deductions are within their own limits. The regular tax takes the larger of the standard deduction and the itemized deductions: state and local taxes up to the 2026 limit ($40,400, less 30% of AGI over $505,000, not below $10,000) plus the others, less the IRC 68 cut above the 37% bracket.

## Worked examples

1. status = single, income = $150,000.00, salt = $10,000.00, item = $5,000.00, iso = $0.00, adj = $0.00 gives amti = $150,000.00, exemption = $90,100.00, tmt = $15,574.00, regular = $24,734.00, amt = $0.00. Source: Rev. Proc. 2025-32 AMT exemption $90,100; Form 6251: standard deduction added back.
2. status = single, income = $200,000.00, salt = $10,000.00, item = $5,000.00, iso = $150,000.00, adj = $0.00 gives amti = $350,000.00, tmt = $67,882.00, regular = $36,734.00, amt = $31,148.00. Source: Form 6251 line 7: 28% × 259,900 − 4,890 (2% of $244,500).
3. status = mfj, income = $600,000.00, salt = $40,000.00, item = $30,000.00, iso = $500,000.00, adj = $0.00 gives amti = $1,070,000.00, exemption = $105,200.00, tmt = $265,254.00, regular = $132,873.50, amt = $132,380.50. Source: Rev. Proc. 2025-32: $140,200 less 50% of AMTI over $1,000,000; SALT limited to $11,900 (IRC 164(b)(7)) and added back (Form 6251 line 2a).
4. status = single, income = $700,000.00, salt = $0.00, item = $0.00, iso = $0.00, adj = $0.00 gives exemption = $0.00, amti = $700,000.00. Source: Rev. Proc. 2025-32: the single exemption is fully phased out at $680,200 of AMTI.

## FAQ

### What is the AMT exemption for 2026?

$90,100 for single and head of household filers and $140,200 for married filing jointly and surviving spouses ($70,100 married filing separately). It falls by 50 cents for each dollar of AMT income over $500,000, or $1,000,000 jointly, so it is gone at $680,200 single and $1,280,400 jointly (IRS Rev. Proc. 2025-32).

### What changed for the AMT in 2026?

The 2025 tax law (P.L. 119-21) set the phase-out thresholds at $500,000 and $1,000,000 for 2026, and the exemption now falls by 50 cents per dollar of AMT income over them instead of 25 cents. More high earners lose their exemption faster, so more of them can owe AMT.

### What are the AMT rates?

26% on the first $244,500 of AMT income after the exemption ($122,250 married filing separately) and 28% above it. Long-term capital gains and qualified dividends keep their 0%, 15%, and 20% rates.

### Why do incentive stock options trigger AMT?

When you exercise ISOs and keep the shares past the end of the year, the spread (the value at exercise minus the price you paid) is not regular income but is added to AMT income. A large spread can push the tentative minimum tax above your regular tax.

### Which deductions are not allowed under the AMT?

The standard deduction and the deduction for state and local taxes. Mortgage interest on a home, gifts to charity, and medical costs over 7.5% of AGI are still allowed.

### Can I get the AMT back later?

AMT caused by timing items such as ISO exercises can give a minimum tax credit (Form 8801) in later years when your regular tax is higher than your tentative minimum tax. This calculator does not figure that credit.

## Sources

- IRS, Rev. Proc. 2025-32 (Internal Revenue Bulletin 2025-45), section 4: Exemption Amounts for Alternative Minimum Tax, rate tables, and standard deduction. https://www.irs.gov/irb/2025-45_IRB (retrieved 2026-10-05)
- IRS, Instructions for Form 6251, Alternative Minimum Tax, Individuals. https://www.irs.gov/instructions/i6251 (retrieved 2026-10-05)
- IRS, Topic no. 556, Alternative minimum tax. https://www.irs.gov/taxtopics/tc556 (retrieved 2026-10-05)