The new york iso amt calculator pairs the federal 26%/28% AMT brackets with New York's 10.9% top-bracket income tax — and NYC residents stack up to 3.876% on top. NY conforms to federal AMT, so there is no second state-level bargain-element hit, but the regular-tax bracket alone can push the combined rate above 50% for high earners. Run your numbers below.
Calculate Your ISO AMT
Use our ISO AMT Calculator to find the optimal number of shares to exercise without triggering AMT.
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How the New York ISO AMT calculator treats ISO exercises
For federal purposes, exercising an Incentive Stock Option (ISO) and holding the shares triggers no regular income tax — but the bargain element (FMV minus strike, times shares) is added to your Alternative Minimum Taxable Income for the year (IRS Publication 525). If your AMT exceeds your regular tax, you owe the difference.
New York conforms to federal AMT treatment. Per the New York Department of Taxation and Finance, the state's AMT calculation uses federal AMTI as its starting point, so the bargain element flows through without an additional state-level add-back at exercise. NY's top marginal rate is 10.9% across progressive 4%–10.9% brackets, and NY does not index brackets for inflation. NYC residents stack an extra 3.876% city tax, pushing combined state + city to roughly 14.8% — and combined with federal AMT (28% top), effective rates on a large exercise can exceed 50%.
The federal AMT calculation has three moving parts (IRS Form 6251):
- The bargain element —
(FMV − strike) × shares exercised— is added to your AMT income for the year. - The AMT exemption is subtracted (a fixed amount that phases out at high incomes).
- The remainder is taxed at 26% up to $239,100 of AMT income, then 28% above (2025 thresholds; 2026 figures publish in late 2025).
The trap for NY holders: because NY conforms to federal AMT, you only owe state tax on the bargain element if federal AMT fires or you later sell. The EquityTax engine handles both layers — the worked examples below show the AMT-free limit and what exercising every share would cost.
Worked examples (New York, 2025)
Each example shows how many ISOs you can exercise before AMT kicks in, using the EquityTax engine. Numbers match what the calculator returns for the inputs shown.
Example 1 — Early-stage IC, $180K salary, single
Inputs: $180,000 W-2, single filer, 10,000 vested ISOs at $2 strike, $12 current FMV.
Result:
- Federal regular tax (without ISO exercise): $32,267
- Federal AMT after ISO exercise (all 10,000 shares): $17,627 in additional federal tax
- New York state tax impact: $9,751.75 baseline regular-tax bill (unchanged by the AMT-free exercise)
- Cash needed at exercise (estimate): $20,000 strike-price check plus the federal AMT bill if you push past the limit
- AMT-free exercise limit: 3,220 shares
At this income, a single filer can exercise about a third of vested ISOs (3,220 of 10,000) without a dollar of federal AMT. Push to all 10,000 and the bargain element jumps to $100,000, AMTI climbs to $280,000, and the federal AMT bill is $17,627 — on top of the $20,000 strike-price check. NY regular tax stays at $9,751.75 because NY mirrors the federal AMT crossover.
Run this scenario in the calculator →
Example 2 — Mid-stage IC, $250K salary, MFJ
Inputs: $250,000 W-2, married filing jointly, 20,000 vested ISOs at $2 strike, $40 current FMV.
Result:
- Federal regular tax: $38,134
- Federal AMT after exercise (all 20,000 shares): $201,524 in additional federal tax
- New York state tax impact: $12,896.75 baseline regular-tax bill
- Cash needed at exercise: $40,000 strike-price check, plus federal AMT exposure if exercising past the limit
- AMT-free exercise limit: 886 shares
The classic AMT trap. FMV jumped from $12 to $40, the AMT-free limit collapsed from 3,220 to 886 shares — under 5% of vested — and exercising everything generates a $760,000 bargain element that pushes AMTI to $1,010,000. The federal AMT bill alone is $201,524. NY tax stays at the $12,896.75 baseline at exercise; the later sale will hit NY's 10.9% top bracket (plus NYC 3.876% for city residents) on the realized gain.
Run this scenario in the calculator →
Example 3 — Late-stage / pre-IPO IC, $350K salary, MFJ
Inputs: $350,000 W-2, married filing jointly, 30,000 vested ISOs at $2 strike, $120 current FMV.
Result:
- Federal regular tax: $62,134
- Federal AMT after exercise (all 30,000 shares): $1,022,284 in additional federal tax
- New York state tax impact: $18,988.13 baseline regular-tax bill
- Cash needed at exercise: $60,000 strike-price check, plus federal AMT exposure
- AMT-free exercise limit: 220 shares
Pre-IPO is where AMT becomes life-altering. Of 30,000 vested shares, only 220 can be exercised AMT-free at this income and FMV. Exercising all 30,000 creates a $3,540,000 bargain element, the AMT exemption fully phases out, and the federal AMT bill is $1,022,284. NY regular tax stays at $18,988.13, but the eventual sale hits NY's 10.9% top bracket (plus NYC 3.876%) on the realized gain — NY has no preferential long-term capital gains rate.
Run this scenario in the calculator →
Strategies for New York option holders
The single biggest lever is timing. Splitting an exercise across two tax years can keep both years below the AMT crossover and turn a five-figure tax bill into a small one — sometimes zero.
- Find your AMT-free limit for this year, exercise at most that number, and roll the rest into next year's exercise window. Example 2 above caps at 886 shares — exercise that, then come back January 1.
- If the bargain element is small, exercise everything that's vested and start the long-term capital gains clock. NY doesn't give you a federal-style LTCG rate, but the clock still matters for federal treatment.
- If you exit a startup mid-year, model the post-IPO scenario — the AMT-free limit shrinks fast as FMV climbs. The Example 1 → Example 3 progression (3,220 → 886 → 220 shares) shows what an FMV ramp does to your exercise capacity.
- NYC residents: factor in the 3.876% city tax. Establishing bona-fide residency outside the city before a liquidity event removes the NYC layer — but NY polices residency aggressively, so the move has to be real.
Open the calculator with your inputs →
FAQ
What is New York's ISO AMT treatment in 2026?
New York conforms to federal AMT, so the bargain element flows through to NY's AMT calculation without an extra state-level add-back at exercise. The state's regular-tax top rate is 10.9% (per the New York Department of Taxation and Finance), and NYC residents stack an additional 3.876%.
How many ISOs can I exercise without triggering AMT in New York?
It depends on your W-2 income, filing status, and the spread between FMV and strike. The EquityTax calculator uses binary search to find your exact AMT-free limit. In the worked examples above, the limit ranged from 220 shares (pre-IPO, $120 FMV) to 3,220 shares (early-stage, $12 FMV) on the same $2 strike.
Do NYC residents pay extra ISO tax?
Yes. NYC residents pay city income tax up to 3.876% on top of NY state tax, pushing the combined state + city rate to roughly 14.8% on top-bracket income. That layer applies to the realized gain at sale, not to a held ISO exercise — but once you sell, the city tax stacks on top of NY's 10.9%.
Should I exercise before or after IPO in New York?
The Example 1 → Example 3 progression shows the cost of waiting: when FMV climbed from $12 to $120 on the same $2 strike, the AMT-free limit fell from 3,220 to 220 shares. Pre-IPO exercises usually give you a much larger AMT-free capacity, but they also carry private-company illiquidity risk. Model both scenarios in the calculator before deciding.
Sources
- IRS Form 6251, Alternative Minimum Tax (Individuals) — exemption amounts, phase-out thresholds, AMT rates.
- IRS Publication 525, Taxable and Nontaxable Income — ISO bargain-element treatment.
- New York Department of Taxation and Finance — state ISO and AMT guidance, federal-conformity rules.
- EquityTax New York ISO AMT Calculator (internal engine, last verified 2026-05-09).
Tax Disclaimer: This content is for educational purposes only. Always consult with a licensed tax professional or certified public accountant before making financial decisions related to equity compensation, tax planning, or investment strategies.
Estimate only — not financial or tax advice. Consult a qualified CPA before making decisions about exercising stock options, selling equity, or other financial moves.