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AMT 2026

The phase-out rate doubled for 2026 and the thresholds dropped $126k. More six-figure households are back in AMT range.

OBBBA made the big AMT exemptions permanent — then quietly pulled more high earners back in: starting 2026 the phase-out thresholds reset to 2018 levels ($500,000 single / $1,000,000 joint, down from $626,350 / $1,252,700) and the phase-out rate doubled from 25% to 50%. Inside that zone, each extra dollar of AMTI loses 50¢ of exemption AND gets taxed at 26–28% — an effective 39–42% marginal rate before your state takes anything. This calculator runs the Form 6251 core: exemption after phase-out, TMT at both rates, and the AMT you actually owe.

Why people use this

High earners exercising ISOs or taking big SALT deductions use it to see whether the parallel tax catches them — with 2026's doubled 50% phase-out and reset $500k/$1M thresholds, the zone where each extra dollar effectively costs 39–42% is back on the map.

How it works

1. Pick filing status — MFS gets half the exemption ($70,100) and half the 26% breakpoint.
2. Enter AMTI: regular taxable income PLUS the add-backs — SALT deduction, standard deduction, ISO bargain element held past year-end, private-activity bond interest.
3. Enter your regular federal tax — AMT is only the excess of tentative minimum tax over it.
4. Read the phased-out exemption, TMT, AMT owed, and whether you are in the doubled phase-out zone.

Common questions

What are the 2026 AMT exemption amounts and phase-outs?

Exemptions (Rev. Proc. 2025-32): $90,100 single/head of household, $140,200 married filing jointly, $70,100 MFS. OBBBA §70107 reset the phase-out starts to $500,000 / $1,000,000 / $500,000 of AMTI and doubled the rate to 50¢ per dollar — so the exemption is fully gone by $680,200 / $1,280,400 / $640,200. The 28% rate kicks in above $244,500 of post-exemption income ($122,250 MFS).

Who gets hit by AMT in 2026?

The classic trigger is exercising incentive stock options and holding past December 31 — the bargain element (FMV − strike) is AMTI with no regular-tax event, phantom income you owe real tax on. The 2026 additions: high earners in high-tax states (the SALT deduction is an AMT add-back, and OBBBA raised the SALT cap to $40,400 — which makes regular tax lower and AMT more likely to exceed it), and anyone with $500k+ of income who was safe under the old $626k/$1.25M thresholds. The consolation: AMT paid on timing items like ISOs becomes a credit (Form 8801) recoverable in later years.

Is the AMT phase-out really an effective 42% rate?

Yes, in the zone. Each additional dollar of AMTI is taxed at 26% or 28% AND removes $0.50 of exemption, which exposes another $0.50 to tax: 28% × 1.5 = 42% effective (39% below the 28% breakpoint) — before state tax. For 2025 the same math was 35% at most. This is why ISO exercise timing and December income decisions changed meaningfully for 2026: spreading exercises across years to stay under $500,000/$1,000,000 AMTI is now worth roughly double what it was.

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