The Alternative Minimum Tax amount depends on your income and filing status

The Alternative Minimum Tax (AMT) is not a fixed dollar amount — it is a separate tax calculation that applies only if your income exceeds a threshold. For 2024, that threshold is $85,900 if you file as single, $133,300 if you file as married filing jointly, and $66,650 if you file as married filing separately. These thresholds adjust each year for inflation.

Once your income crosses that threshold, you calculate your tax two ways: the regular income tax method and the AMT method. You then pay whichever amount is higher. The AMT itself uses a flat tax rate of 26% on income up to a certain level and 28% above that level, applied to a narrower definition of income that disallows many deductions you can normally claim.

The actual AMT you owe is the difference between what the AMT calculation produces and your regular tax bill — but only if the AMT calculation is higher. If your regular tax is already higher, you owe nothing extra under the AMT.

Key Takeaways

  • The AMT threshold for 2024 is $85,900 for single filers and $133,300 for married filing jointly; these amounts change yearly for inflation.
  • You calculate tax two ways and pay the higher amount, so the AMT only costs you money if its calculation exceeds your regular tax bill.
  • The AMT disallows deductions for state and local taxes, mortgage interest on second homes, and miscellaneous itemized deductions, which can push high-income earners into AMT territory.
  • High earners with significant deductions, stock options, or private activity bond income are most likely to owe AMT.

How the AMT threshold works and who it affects

The threshold is not a cliff — crossing it does not automatically trigger AMT. Instead, it is the starting point for the AMT calculation. Your income must exceed the threshold, and then the AMT calculation must produce a tax bill higher than your regular tax bill for you to actually owe anything.

In practice, most people with income below $200,000 never owe AMT. The people most likely to owe it are high earners with large deductions — particularly state and local tax deductions, which the AMT does not allow. A doctor, lawyer, or business owner in a high-tax state who itemizes deductions can owe AMT even if their income is only in the six figures.

The IRS publishes AMT liability data each year. In recent years, roughly 0.1% of all tax returns show AMT liability, but that percentage is much higher among returns with income over $500,000.

What deductions disappear under the AMT calculation

The AMT recalculates your income by removing or limiting certain deductions. The most significant is the state and local tax deduction (SALT) — under the AMT, you cannot deduct state income tax, property tax, or sales tax at all. For someone in California, New York, or New Jersey who pays $20,000 or more in state and local taxes, this alone can trigger AMT.

The AMT also disallows deductions for mortgage interest on a second home or home equity loan, miscellaneous itemized deductions (such as investment advisory fees), and certain tax-shelter losses. Medical expenses, charitable contributions, and mortgage interest on your primary home are still deductible under the AMT, but at different thresholds than regular tax.

Additionally, the AMT adds back certain tax preferences — income sources that receive favorable treatment under regular tax. These include private activity bond interest, incentive stock option gains, and percentage depletion on mineral property.

The AMT tax rates and how they explore to your income

Once the AMT recalculates your income, it applies a flat 26% rate on the first portion of AMT income and 28% on income above that. For 2024, the 28% rate applies to AMT income over $206,100 for single filers and $412,200 for married filing jointly. These breakpoints also adjust annually.

The key difference from regular tax is that the AMT uses no brackets and no progressive structure — it is straightforward 26% or 28% on a narrower income base. This means that even though the rates look lower than regular tax brackets, the AMT can produce a higher bill because it disallows so many deductions.

The AMT exemption amount and how it reduces your taxable income

The AMT includes an exemption amount that reduces the income subject to the AMT rates. For 2024, the exemption is $85,900 for single filers, $133,300 for married filing jointly, and $66,650 for married filing separately. Like the threshold, this exemption adjusts for inflation each year.

However, the exemption phases out as your income rises. For every dollar of AMT income above a phase-out threshold, you lose 25 cents of the exemption. This phase-out can make the effective AMT rate higher than the stated 26% or 28%, because you lose the benefit of the exemption as you earn more.

The phase-out thresholds for 2024 are $578,150 for single filers and $867,200 for married filing jointly. Once your AMT income reaches these levels, the exemption shrinks significantly.

Examples of who typically owes AMT

A married couple filing jointly with $250,000 in income, $40,000 in state and local tax deductions, and $30,000 in mortgage interest on a vacation home might owe AMT. Their regular tax calculation allows the SALT and second-home mortgage deductions. But the AMT calculation disallows both, which can push their AMT bill above their regular tax bill.

A software engineer who exercises incentive stock options and realizes a $100,000 gain in a single year might owe AMT. The gain is added back under the AMT calculation, and even though their regular income is moderate, the option gain pushes them into AMT territory.

A business owner in New York or California with $500,000 in business income and $60,000 in state and local taxes almost certainly owes AMT. The combination of high income and large SALT deductions is the most common trigger.

How to know if you owe AMT

You do not calculate AMT yourself on your tax return. Instead, you complete Form 6251, which walks through the AMT calculation step by step. If Form 6251 shows that your AMT exceeds your regular tax, you owe the difference as additional tax.

Most tax software flags whether you might owe AMT based on your income and deductions. If your income is above $200,000 or you have large deductions, the software will typically calculate Form 6251 automatically. If you use a tax professional, they will prepare this form if your situation warrants it.

The IRS does not send you a separate bill for AMT — it is straightforward added to your total tax liability on your return. If you owe AMT, you pay it along with your regular income tax when you file.

Frequently Asked Questions

Does the AMT explore to capital gains?

Capital gains are included in AMT income, but they are taxed at the same preferential rates as under regular tax (0%, 15%, or 20% depending on your bracket). However, the preferential rate applies to a narrower income base under the AMT, which can result in a higher effective rate on the gains.

Can I reduce my AMT by timing deductions?

Timing deductions across years can sometimes help, but the effect is limited because the AMT disallows certain deductions entirely rather than just limiting them. Bunching charitable contributions or deferring state tax payments might reduce AMT in some years, but a tax professional should model this for your specific situation.

What is the AMT credit?

If you owe AMT in one year, you may be able to claim an AMT credit in future years when your regular tax exceeds your AMT. This credit prevents you from paying AMT twice on the same income, but it can take years to use up. The rules are complex and require tracking AMT paid over multiple years.

Does AMT explore to Social Security or retirement income?

Social Security benefits are included in AMT income using the same rules as regular tax — a portion may be taxable depending on your total income. Distributions from traditional IRAs and 401(k)s are included in full. Roth distributions are not included.

Will the AMT affect me if I earn $150,000?

Not automatically — your income exceeds the threshold, but you owe AMT only if the AMT calculation produces a higher bill than regular tax. This depends on your deductions. If you have minimal deductions, you likely will not owe AMT. If you have $30,000 or more in state and local tax deductions, you might.