Alternative Minimum Tax (AMT): Complete Guide for 2026

What Is the Alternative Minimum Tax?

The Alternative Minimum Tax (AMT) is a separate federal income tax system that runs parallel to the regular income tax. Taxpayers subject to the AMT must calculate their tax liability under both the regular system and the AMT system and pay the higher of the two amounts.

The AMT achieves this by disallowing many of the deductions, exemptions, and credits available under the regular tax system. It adds back certain "tax preference items" and "adjustments" to your income, applies a different set of rates, and allows only a specific exemption amount before applying those rates.

If your calculated AMT liability exceeds your regular tax liability, you owe the difference as Alternative Minimum Tax. This amount is reported on your tax return and added to the regular tax you already owe.

The AMT was originally enacted in 1969 after a congressional report revealed that 155 high-income taxpayers paid zero federal income tax by using generous tax shelters. The original AMT targeted a very small number of wealthy taxpayers. However, because the AMT exemption was not initially indexed for inflation, the number of taxpayers subject to the AMT grew dramatically over time.

The American Taxpayer Relief Act of 2012 permanently indexed the AMT exemption for inflation, and the Tax Cuts and Jobs Act of 2017 significantly increased the exemption amounts and phase-out thresholds through 2025. For 2026, the exemption amounts continue to be adjusted for inflation under the indexing provisions.

Use our tax refund calculator to estimate your overall tax liability considering both regular tax and potential AMT.

Why the AMT Exists

The AMT exists to ensure that taxpayers who benefit from certain tax preferences still pay a minimum amount of federal income tax. The core principle is that no taxpayer should be able to use deductions, credits, and exclusions to eliminate their entire tax liability.

Congress designed the AMT to recapture tax benefits that are seen as overly generous or that allow high-income taxpayers to avoid paying their fair share. The AMT accomplishes this by:

• Disallowing the standard deduction — You must calculate AMT using your AMT income without the benefit of the standard deduction
• Disallowing personal and dependency exemptions — These are not permitted in the AMT calculation
• Limiting itemized deductions — State and local taxes, miscellaneous itemized deductions, and certain medical expenses are not deductible for AMT purposes
• Adding back tax preference items — Certain types of income that receive favorable regular tax treatment are fully taxed under AMT
• Applying a broader income base — The AMT tax base (Alternative Minimum Taxable Income or AMTI) is generally larger than regular taxable income

The effectiveness of the AMT in preventing tax avoidance has been debated. Some argue that the AMT has become a trap for middle-income taxpayers in high-tax states, while others maintain that it serves an important function in maintaining tax equity.

The Tax Cuts and Jobs Act of 2017 significantly reduced the number of taxpayers subject to AMT by raising exemption amounts and phase-out thresholds. Before the TCJA, approximately 5 million taxpayers were subject to AMT. After the TCJA, that number fell to fewer than 200,000. The 2026 inflation-adjusted exemptions continue this trend of limited AMT applicability.

Despite the reduced reach, understanding the AMT remains important for taxpayers with high state and local taxes, those exercising incentive stock options, and individuals with significant capital gains or other preference items.

How the AMT System Works

The AMT calculation process works as follows:

Step 1: Calculate regular taxable income. Start with your adjusted gross income, subtract your standard deduction or itemized deductions, and subtract personal and dependency exemptions (if applicable in your tax year) to arrive at regular taxable income.

Step 2: Compute Alternative Minimum Taxable Income (AMTI). Start with your regular taxable income and add back all "tax preference items" and "adjustments" required by the AMT system. Preference items include tax-exempt interest from private activity bonds, depletion deductions exceeding cost basis, and the bargain element of incentive stock options. Adjustments include adding back state and local taxes deducted, miscellaneous itemized deductions, and certain medical expenses. You also add back the standard deduction (if you claimed it) and personal exemptions.

Step 3: Subtract the AMT exemption amount. Subtract the applicable exemption based on your filing status. For 2026, the exemption is $88,100 for single filers and $137,000 for married couples filing jointly. The exemption phases out at higher income levels.

Step 4: Apply AMT rates. Apply the AMT rate schedule to the remaining amount (called the Alternative Minimum Tax Base). The 2026 AMT rates are 26% on the first $239,100 of AMT base (half that for married filing separately) and 28% on AMT base above that threshold.

Step 5: Compare to regular tax. Compare your tentative minimum tax (the result from Step 4) to your regular tax liability. If the tentative minimum tax is higher, you owe the difference as Alternative Minimum Tax.

This parallel calculation means that taxpayers in AMT must track two sets of tax numbers. The complexity of the AMT calculation is one reason why tax preparation software is widely used by those potentially subject to this tax.

2026 AMT Exemption Amounts & Phase-Outs

The AMT exemption amount is the portion of your Alternative Minimum Taxable Income that is not subject to AMT. For 2026, the exemption amounts are as follows:

The exemption phase-out reduces the exemption amount by 25 cents for every dollar of AMTI above the phase-out threshold. This means the exemption is completely phased out at the "Phase-Out Complete" amounts shown above.

Example of phase-out calculation: If you are a single filer with AMTI of $700,000 in 2026, your exemption phase-out is calculated as follows:

• Excess AMTI over threshold: $700,000 - $626,350 = $73,650
• Phase-out reduction: $73,650 × 25% = $18,413
• Available exemption: $88,100 - $18,413 = $69,687

The phase-out effectively creates a marginal AMT rate bubble where the effective tax rate is higher than the stated 28% because each additional dollar of income reduces your exemption, increasing your taxable AMT base.

At the peak of the phase-out (where the exemption is being reduced), the effective marginal AMT rate can reach approximately 35% because the 28% rate applies to income that also triggers a 25-cent exemption reduction per dollar. This creates a stealth bracket that many taxpayers do not anticipate.

The exemption amounts are adjusted annually for inflation, so these figures will change for future tax years. The indexing helps prevent "bracket creep" where inflation pushes more taxpayers into AMT without any real increase in their purchasing power.

AMT Rates: 26% and 28% Brackets

The AMT uses a simplified two-bracket rate structure, unlike the regular income tax system which has seven brackets. For 2026, the AMT rates are:

A significant difference from the regular tax system is that the AMT does not have capital gains preferences. Long-term capital gains and qualified dividends are generally taxed at the same rates under AMT as under the regular tax system. However, because they increase your AMTI and may reduce your exemption (through the phase-out), capital gains can indirectly increase your AMT liability.

The 26% and 28% AMT rates apply to the AMT base after subtracting the exemption amount. This means the effective AMT rate on your total income is often much lower than these rates suggest because a significant portion of your income is shielded by the exemption.

AMT calculation example: A married couple filing jointly with AMTI of $500,000 in 2026:

• AMTI: $500,000
• AMT exemption: $137,000 (fully available — below phase-out threshold of $1,042,800)
• AMT base: $500,000 - $137,000 = $363,000
• Tax at 26% on first $239,100: $62,166
• Tax at 28% on remaining $123,900: $34,692
• Tentative minimum tax: $96,858
• If regular tax is $80,000, the AMT owed is $16,858

AMT Preference Items and Adjustments

AMT preference items and adjustments are the specific tax benefits that the AMT system disallows or limits. These items are added back to your regular taxable income to compute your AMTI. Understanding these items is critical for identifying whether you might be subject to AMT.

Common AMT preference items include:

• Tax-exempt interest from private activity bonds — Interest from certain private activity bonds issued after August 7, 1986 is tax-exempt for regular tax purposes but is a preference item for AMT
• Depletion deduction — The excess of percentage depletion over the cost basis of the property
• Intangible drilling costs — Excess IDCs from oil and gas properties
• Tax-exempt interest on specified private activity bonds — Must be included in AMTI

Common AMT adjustments include:

• State and local taxes — Any state and local income, sales, or property taxes deducted on Schedule A must be added back for AMT purposes. This is one of the most common AMT triggers.
• Miscellaneous itemized deductions — Deductions subject to the 2% AGI floor (such as tax preparation fees, investment expenses) are not allowed for AMT
• Medical expenses — For AMT, the threshold is 10% of AGI instead of 7.5% for regular tax. If you claimed medical expenses between 7.5% and 10% of AGI, the difference is an AMT adjustment
• Standard deduction — If you claimed the standard deduction for regular tax, it must be added back for AMT (though you may be able to claim certain AMT-specific itemized deductions)
• Personal and dependency exemptions — These must be added back for AMT
• Incentive stock options (ISOs) — The bargain element (difference between exercise price and fair market value) at exercise is an AMT preference item, even if the shares are not yet sold
• Depreciation adjustments — Different depreciation methods apply under AMT (generally the Alternative Depreciation System or ADS), which may result in lower depreciation deductions
• Passive activity loss adjustments — Certain passive losses allowed for regular tax may be restricted for AMT
• Net operating loss (NOL) adjustments — AMT NOL is limited to 80% of AMTI and is computed differently

The largest and most common AMT preference item for most taxpayers is the state and local tax deduction. Taxpayers in high-tax states like California, New York, New Jersey, Illinois, and Massachusetts are disproportionately affected.

The Tax Cuts and Jobs Act limited the state and local tax deduction to $10,000 for regular tax purposes, which significantly reduced the AMT impact for many taxpayers who previously deducted large amounts of state and local taxes.

Form 6251 Walkthrough

Form 6251 (Alternative Minimum Tax — Individuals) is the IRS form used to compute the AMT. Understanding this form helps you see exactly how the AMT calculation works and whether you need to complete it.

Part I — Alternative Minimum Taxable Income (AMTI):

• Line 1: Enter your regular taxable income from Form 1040
• Lines 2-15: Enter adjustments and preferences, including:
  • Line 2: Standard deduction (if claimed) added back
  • Line 3: Medical expense adjustment (difference between 7.5% and 10% thresholds)
  • Line 4: State and local tax deduction added back
  • Line 5: Miscellaneous itemized deductions added back
  • Line 6: Personal and dependency exemptions added back
  • Line 7: Investment interest expense adjustment
  • Line 8: Depreciation adjustment
  • Line 9: Passive activity loss adjustments
  • Line 10: Incentive stock option adjustment
  • Line 11: Private activity bond interest
  • Lines 12-15: Other adjustments and preferences
• Line 16: Total adjustments and preferences (sum of Lines 2-15)
• Line 17: AMTI (Line 1 + Line 16)

Part II — Alternative Minimum Tax:

• Line 18: AMT exemption amount (based on filing status from the table)
• Line 19: AMT base (Line 17 minus Line 18; if zero or less, stop — no AMT)
• Line 20: Tentative minimum tax: 26% of AMT base up to the threshold amount plus 28% of any excess
• Line 21: Alternative Minimum Tax (Line 20 minus your regular tax plus any foreign tax credit)

Who must file Form 6251? You must file Form 6251 if your AMTI exceeds the applicable exemption amount. However, even if your AMTI is below the exemption, you should check the form's instructions to determine if you are required to file. Most tax preparation software will automatically determine whether you need to file Form 6251.

The form is relatively straightforward for simple situations but becomes complex when dealing with ISOs, passive activities, depreciation recapture, and other specialized items. Taxpayers with complex situations should use professional tax software or consult a tax professional.

Our tax refund calculator can help you estimate your regular tax liability as a starting point for understanding your AMT exposure.

AMT Credit (Form 8801)

The AMT credit (Form 8801) allows taxpayers who paid AMT in prior years to recapture some of that tax in future years when their AMT liability is lower. The credit exists because many AMT preference items relate to the timing of income and deductions rather than permanent exclusions.

How the AMT credit works:

• When you pay AMT because of timing differences (such as ISO exercises or depreciation differences), the tax you pay is effectively a prepayment of future regular tax
• In subsequent years, you can claim a credit against your regular tax liability for the AMT you previously paid
• The credit is limited to the excess of your regular tax over your tentative minimum tax in the credit year
• The credit can be carried forward indefinitely until fully used

Form 8801 (Credit for Prior Year Minimum Tax) is used to calculate the AMT credit. The form requires information from your current year Form 6251 and prior year AMT returns.

Minimum tax credit vs AMT credit: The credit is often called the "minimum tax credit" because it represents the portion of AMT paid that is attributable to timing differences rather than permanent differences. Permanent preference items (like private activity bond interest) do not generate a credit because the tax is owed permanently.

AMT credit example: You paid $10,000 in AMT in 2023 due to exercising incentive stock options. In 2026, your regular tax is $25,000 and your tentative minimum tax is $22,000. You can claim an AMT credit of up to $3,000 ($25,000 - $22,000), reducing your regular tax to $22,000. The remaining $7,000 credit carries forward to future years.

The AMT credit can be an important tax planning tool. Taxpayers who pay AMT in one year due to an ISO exercise or large depreciation deduction should track their AMT credit carryforward and claim it in future years when their AMT situation is more favorable.

Who Is Most at Risk for AMT?

While the TCJA significantly reduced the number of taxpayers subject to AMT, certain groups remain at higher risk:

1. Taxpayers in high-tax states: Even with the $10,000 SALT deduction cap for regular tax, the AMT disallowance of state and local taxes means that taxpayers in states with high income and property taxes remain disproportionately affected. California, New York, New Jersey, Massachusetts, Illinois, Connecticut, and Oregon residents are among the most impacted.

2. Large families: The AMT disallows personal and dependency exemptions. Taxpayers with four or more dependents who claim substantial exemptions on their regular return may find those exemptions eliminated in the AMT calculation, potentially triggering AMT liability.

3. Taxpayers with incentive stock options (ISOs): The bargain element of ISOs at exercise is an AMT preference item, even if the shares are not sold. This can create large AMT liabilities without the cash to pay them, particularly if the stock price later declines.

4. Taxpayers with significant capital gains: While capital gains are generally taxed the same way under AMT, they increase overall income, which can trigger AMT exemption phase-outs and indirectly cause AMT liability.

5. Taxpayers with private activity bond interest: A significant amount of tax-exempt interest from private activity bonds can push a taxpayer into AMT territory.

6. Residents of high-cost areas: High mortgage interest and property taxes in expensive real estate markets can be limited under AMT (mortgage interest is limited to acquisition indebtedness of $750,000, though this is the same as regular tax).

7. Taxpayers with large miscellaneous itemized deductions: Unreimbursed employee expenses, investment fees, and tax preparation costs that were deductible for regular tax are entirely disallowed for AMT.

If you fall into any of these categories, you should estimate your AMT liability before filing. Use our tax refund calculator as a starting point, and consider professional tax preparation to ensure you are accurately calculating both regular and AMT liability.

Incentive Stock Options and AMT

Incentive stock options (ISOs) create one of the most significant AMT traps. When you exercise ISOs and hold the shares (a disqualifying disposition), the bargain element — the difference between the exercise price and the fair market value of the shares on the exercise date — is an AMT preference item.

How ISOs trigger AMT:

• For regular tax: No tax is due when you exercise ISOs; tax is deferred until you sell the shares
• For AMT: The bargain element at exercise is included as a preference item on Form 6251
• If the stock price is high at exercise but drops before you sell, you could owe AMT on the higher value even if you never realized the gain in cash

ISO AMT planning strategies:

• Exercise early in the year: This gives you more time to sell the shares before year-end if the price drops
• Consider disqualifying dispositions: Selling ISO shares in the same calendar year as exercise avoids the AMT preference because the gain is treated as ordinary income for regular tax purposes
• Exercise in low-income years: Exercise ISOs in years when your income is lower and you are further from the AMT phase-out thresholds
• Track AMT credit carryforwards: If you pay AMT on ISO exercises, you may be able to claim the AMT credit in future years
• Use Form 6251 worksheets: Calculate your projected AMT liability before exercising ISOs to understand the tax consequences

The ISO/AMT trap was particularly severe during the dot-com era when many employees exercised ISOs at peak valuations only to watch share prices collapse. They were left with large AMT bills based on values they never realized. While ISOs remain a significant AMT trigger, awareness of the rules helps taxpayers plan around them.

If you hold ISOs and are considering exercising them, consult a tax professional to model the AMT implications before you act. The difference between a disqualifying disposition (sale in the same year) and a qualifying disposition (sale more than two years after grant and one year after exercise) can mean thousands of dollars in AMT liability.

AMT Planning Strategies

While the AMT cannot always be avoided, several strategies can help minimize your exposure:

1. Manage state and local tax timing: If you are subject to AMT, accelerating state tax payments into the current year will not provide a regular tax benefit (because of the $10,000 SALT cap) and will not help with AMT (because state taxes are disallowed). Deferring state tax payments to a non-AMT year can help.

2. Time your itemized deductions: If you are in AMT one year, certain itemized deductions provide no benefit. Consider bunching medical expenses and charitable contributions into non-AMT years when they can reduce your regular tax.

3. Exercise ISOs strategically: As discussed above, timing ISO exercises to minimize AMT impact is critical. Consider exercising in years with lower overall income or making disqualifying dispositions to avoid the AMT preference.

4. Manage passive activity losses: If you have passive activity losses that are limited for regular tax, they may be treated differently for AMT. Coordinating the timing of passive activity income and losses can help minimize AMT.

5. Consider municipal bonds carefully: Tax-exempt interest from private activity bonds is a preference item for AMT. If you are at risk for AMT, consider investing in governmental municipal bonds (which are exempt from AMT) rather than private activity bonds.

6. Use retirement contributions strategically: Traditional IRA, SEP IRA, and Solo 401(k) contributions reduce your AGI and AMTI equally, so they are equally beneficial under both systems. Maximizing retirement contributions can help keep your income below AMT phase-out thresholds.

7. Health Savings Account (HSA) contributions: HSA contributions reduce both regular taxable income and AMTI, providing dual tax benefits. HSAs are one of the most tax-efficient savings vehicles for AMT-sensitive taxpayers.

8. Convert to Roth IRA: Roth IRA conversions in non-AMT years can reduce future required minimum distributions (RMDs) and help manage long-term AMT exposure in retirement.

9. Claim the AMT credit: If you paid AMT in prior years due to timing differences, ensure you file Form 8801 to claim any available AMT credit in the current year.

10. Model your taxes: The most effective AMT planning strategy is to model your tax liability under both systems before year-end. Tax projection software or a qualified CPA can help you understand whether anticipated transactions will trigger AMT.

AMT planning is complex because it requires coordinating across multiple tax years and considering the interaction between the regular tax and AMT systems. Professional tax advice is recommended for taxpayers with significant AMT exposure.

Our related guide on tax brackets for 2025 and 2026 can help you understand your regular tax rate structure in relation to your potential AMT rate.

State and Local Tax Impact on AMT

The interaction between state and local taxes and the AMT is one of the most important factors in determining AMT liability. For many taxpayers in high-tax states, the disallowance of state and local tax deductions is the single largest AMT adjustment.

Regular tax treatment of SALT: Under the Tax Cuts and Jobs Act, state and local taxes (income, sales, and property) are limited to a $10,000 deduction ($5,000 for married filing separately) on Schedule A.

AMT treatment of SALT: For AMT purposes, state and local taxes are entirely disallowed. Even the $10,000 deduction available for regular tax must be added back in the AMT calculation. This means every dollar of state and local tax you paid — up to $10,000 — is an AMT adjustment that increases your AMTI.

Impact on high-tax states: Taxpayers in states with high income tax rates (California 13.3%, New York 10.9%, New Jersey 10.75%, Oregon 9.9%) and high property taxes (Texas, New Jersey, Illinois, Connecticut) are most affected. A taxpayer paying $10,000 in SALT for regular tax purposes adds that full $10,000 back to their AMTI.

State-specific AMT considerations: Some states also have their own AMT systems that operate alongside the federal AMT. California, for example, has a state AMT with different exemption amounts and rules. Taxpayers in these states must navigate both federal and state AMT calculations.

SALT planning in AMT years: If you know you are subject to AMT in a given year, consider deferring property tax payments that are due early in the following year. Since SALT payments provide no regular tax benefit (limited to $10,000) and no AMT benefit (entirely disallowed), there is no advantage to accelerating them.

The SALT-AMT interaction is a prime example of how federal tax policy affects residents of different states differently. Tax reform proposals that address either SALT deductibility or AMT reform would significantly change the landscape for taxpayers in high-tax jurisdictions.

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