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How does Alternative Minimum Tax work for individuals

TY 2025 Individual Income Tax 6 sources ↓ 2026-09-28 Reviewed before publication by Noah

Question askedHow does the Alternative Minimum Tax (AMT) work for individuals?

Quick answer: For 2025 and 2026, AMT is a parallel tax calculation that adds back certain deductions and tax-preference items to your regular taxable income, then taxes that larger amount (after an exemption) at 26% or 28%; you pay whichever is higher — your regular tax or this "tentative minimum tax."

What it is

The AMT exists because ordinary tax rules give favorable treatment to certain income and expenses. IRS Publication 559 explains that the tax laws give special treatment to certain types of income and allow special deductions and credits for certain types of expenses, and the AMT was enacted so taxpayers who benefit from these laws still pay at least a minimum amount of tax. In general, the AMT is the excess of the tentative minimum tax over the regular tax shown on the return.

How it works

  1. Start with a broader income base. Under IRC § 55(b)(1)(D), "alternative minimum taxable income" means the taxable income of the taxpayer for the taxable year determined with the adjustments provided in section 56 and section 58, and increased by the amount of the items of tax preference described in section 57.

  2. Subtract an exemption amount. The Code defines "taxable excess" as AMTI minus the exemption amount (IRC § 55(b)(1)(B)). The exemption amounts written into the Code text are, for taxpayers other than corporations, $78,750 in the case of a joint return or a surviving spouse, $50,600 in the case of an individual who is not married and not a surviving spouse, 50 percent of the joint-return amount for a married individual filing separately, and $22,500 in the case of an estate or trust. Important: these Code figures do not match current-year numbers — IRS Publication 17 states that for tax year 2026, the AMT exemption amount is increased to $88,100 ($137,000 if married filing jointly or qualifying surviving spouse; $68,500 if married filing separately), and the income levels at which the AMT exemption begins to phase out have increased to $626,350 ($1,252,700 if married filing jointly or qualifying surviving spouse). The Code excerpt provided is stripped of inflation-adjustment mechanics and effective dates, so always use the current published (inflation-adjusted) figures rather than the bare statutory numbers.

  3. Exemption phases out at high income. IRC § 55(d)(2) provides that the exemption amount shall be reduced (but not below zero) by an amount equal to 25 percent of the amount by which alternative minimum taxable income exceeds specified thresholds — again, use the current inflation-adjusted thresholds noted above, not the older dollar figures embedded in the statute.

  4. Apply the tentative minimum tax rates. Once you have "taxable excess," IRC § 55(b)(1)(A) sets the rate structure: the tentative minimum tax for the taxable year is the sum of 26 percent of so much of the taxable excess as does not exceed $175,000, plus 28 percent of so much of the taxable excess as exceeds $175,000. Married individuals filing separately use half that breakpoint. In the case of a married individual filing a separate return, the dollar amounts are substituted at 50 percent, with marital status determined under section 7703.

  5. Compare to regular tax. If tentative minimum tax exceeds your regular tax, the difference is your AMT, due in addition to regular tax.

  6. Special capital gains rule. Publication 550 notes that these capital gain rates are also used in figuring alternative minimum tax, so preferential rates on long-term gains and qualified dividends carry over into the AMT computation rather than being taxed at 26%/28%.

Example (illustrative)

A married couple filing jointly with AMTI of $300,000 in 2026 would subtract the $137,000 exemption (assuming no phase-out applies) to get $163,000 of taxable excess, taxed entirely at 26% since it's under $175,000 — a tentative minimum tax of about $42,380. If their regular tax is lower, the difference becomes AMT owed.

Risks and limits

  • A minor child's AMT exemption is capped: IRC § 59(j)(1) limits it to such child's earned income for the taxable year, plus $5,000.
  • If you paid AMT in an earlier year, you may recover part of it later. Publication 559 mentions the decedent may be eligible for a minimum tax credit, reported on Form 8801, Credit for Prior Year Minimum Tax—Individuals, Estates, and Trusts.
  • Net operating loss carrybacks require refiguring AMT too: Publication 536 instructs taxpayers to use refigured taxable income to refigure total tax liability, including alternative minimum tax, and any credits based on AGI, MAGI, or tax liability.

In practice

AMT doesn't eliminate the benefit of preference items entirely — it caps how much they can reduce your total tax below the tentative minimum tax floor, and any AMT paid due to timing differences may generate a credit usable in future years. Form 6251 is used to determine whether AMT applies, as referenced in Publication 559.

Given the complexity of exemption phase-outs, preference-item add-backs, and credit carryforwards, it's worth having a CPA run the actual Form 6251 calculation for your specific income and deduction mix.

Sources relied upon

  1. IRS publication IRS Publication 559 — Survivors, Executors, and Administrators — Credits, Other Taxes, and Payments › Other Taxes, p. 10 · see it highlighted in context · official source (p. 10) ↗
    “The tax laws give special treatment to certain types of income and allow special deductions and credits for certain types of expenses. The AMT was enacted so taxpayers who benefit from these laws still pay at least a minimum amount of tax. In general, the AMT is the excess of the tentative minimum tax over the regular tax shown on the return.”
  2. Statute 26 U.S.C. § 55 — Alternative minimum tax imposed — (b) Tentative minimum tax › (1) Noncorporate taxpayers · see it highlighted in context · official source ↗ · same text at Cornell LII ↗
    “(D) Alternative minimum taxable income The term “alternative minimum taxable income” means the taxable income of the taxpayer for the taxable year— (i) determined with the adjustments provided in section 56 and section 58, and (ii) increased by the amount of the items of tax preference described in section 57.”
  3. Statute 26 U.S.C. § 55 — Alternative minimum tax imposed — (d) Exemption amount › (1) Exemption amount for taxpayers other than corporations · see it highlighted in context · official source ↗ · same text at Cornell LII ↗
    “For purposes of this section— (1) Exemption amount for taxpayers other than corporations In the case of a taxpayer other than a corporation, the term “exemption amount” means— (A) $78,750 in the case of— (i) a joint return, or (ii) a surviving spouse, (B) $50,600 in the case of an individual who— (i) is not a married individual, and (ii) is not a surviving spouse, (C) 50 percent of the dollar amou…”
  4. IRS publication IRS Publication 17 — Your Federal Income Tax (Individuals) — What’s New, p. 4 · see it highlighted in context · official source (p. 4) ↗
    “Alternative minimum tax (AMT) exemption amount increased. The AMT exemption amount is increased to $88,100 ($137,000 if married filing jointly or qualifying surviving spouse; $68,500 if married filing separately). The income levels at which the AMT exemption begins to phase out have increased to $626,350 ($1,252,700 if married filing jointly or qualifying surviving spouse).”
  5. Statute 26 U.S.C. § 55 — Alternative minimum tax imposed — (d) Exemption amount › (2) Phase-out of exemption amount · see it highlighted in context · official source ↗ · same text at Cornell LII ↗
    “The exemption amount of any taxpayer shall be reduced (but not below zero) by an amount equal to 25 percent of the amount by which the alternative minimum taxable income of the taxpayer exceeds— (A) $150,000 in the case of a taxpayer described in paragraph (1)(A), (B) $112,500 in the case of a taxpayer described in paragraph (1)(B), and (C) 50 percent of the dollar amount applicable under subparag…”
  6. Statute 26 U.S.C. § 55 — Alternative minimum tax imposed — (b) Tentative minimum tax › (1) Noncorporate taxpayers · see it highlighted in context · official source ↗ · same text at Cornell LII ↗
    “For purposes of this part— (1) Noncorporate taxpayers In the case of a taxpayer other than a corporation— (A) In general The tentative minimum tax for the taxable year is the sum of— (i) 26 percent of so much of the taxable excess as does not exceed $175,000, plus (ii) 28 percent of so much of the taxable excess as exceeds $175,000.”
  7. Statute 26 U.S.C. § 55 — Alternative minimum tax imposed — (b) Tentative minimum tax › (1) Noncorporate taxpayers · see it highlighted in context · official source ↗ · same text at Cornell LII ↗
    “(C) Married individual filing separate return In the case of a married individual filing a separate return, subparagraph (A) shall be applied by substituting 50 percent of the dollar amount otherwise applicable under clause (i) and clause (ii) thereof. For purposes of the preceding sentence, marital status shall be determined under section 7703.”
  8. IRS publication IRS Publication 550 — Investment Income and Expenses — Reporting Capital Gains and Losses › Capital Gain Tax Rates, p. 103 · see it highlighted in context · official source (p. 103) ↗
    “Alternative minimum tax. These capital gain rates are also used in figuring alternative minimum tax.”
  9. Statute 26 U.S.C. § 59 — Other definitions and special rules — (e) Optional 10-year writeoff of certain tax preferences › (5) Dispositions · see it highlighted in context · official source ↗ · same text at Cornell LII ↗
    “(j) Treatment of unearned income of minor children › (1) In general In the case of a child to whom section 1(g) applies, the exemption amount for purposes of section 55 shall not exceed the sum of— (A) such child’s earned income (as defined in section 911(d)(2)) for the taxable year, plus (B) $5,000.”
  10. IRS publication IRS Publication 559 — Survivors, Executors, and Administrators — Credits, Other Taxes, and Payments › Other Taxes, p. 10 · see it highlighted in context · official source (p. 10) ↗
    “If the decedent paid AMT in a previous year or had a credit carryforward, the decedent may be eligible for a minimum tax credit. See Form 8801, Credit for Prior Year Minimum Tax—Individuals, Estates, and Trusts.”
  11. IRS publication IRS Publication 536 — Net Operating Losses — How To Claim an NOL Deduction › Deducting a Carryback, p. 8 · see it highlighted in context · official source (p. 8) ↗
    “Finally, use your refigured taxable income (Form 1045, line 15, using the “After carryback” column) to refigure your total tax liability. Refigure your income tax, your alternative minimum tax, and any credits that are based on or limited by your AGI, modified AGI (MAGI), or tax liability.”

Quoted passages are extracted verbatim from the source documents by the citation system — they cannot be fabricated by the AI.

General information for tax year 2025 — not tax advice for your situation, and no client relationship is created. Full disclaimer.
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