ISO exercise & AMT

Exercising incentive stock options creates a "bargain element" that counts as income for the Alternative Minimum Tax — a surprise bill in April. Size it, then find the largest exercise that stays $0-AMT. (OBBBA reset the 2026 AMT phase-out, so last year's math is stale.)

1 · Size the AMT on a full exercise

Send the grant and the holder's other income to /v1/equity-comp/iso.

curl -X POST https://api.numeratica.com/v1/equity-comp/iso \
  -H "Authorization: Bearer nmr_sk_test_xxx" \
  -H "Content-Type: application/json" \
  -d '{
    "tax_year": 2026, "filing_status": "single",
    "shares": 10000, "strike_price": 2, "fmv_at_exercise": 22,
    "ordinary_income": 200000
  }'

{
  "result_id": "eqc-iso_9a57d8261deaf54a",
  "engine_version": "equity-comp-1.0.0",
  "result": {
    "bargain_element": 200000,
    "amt_without_exercise": 0,
    "amt_with_exercise": 45148,
    "incremental_amt": 45148,
    "amt_credit_carryforward": 45148
  },
  "disclaimer": "Calculation engine output for informational purposes only; not tax or financial advice."
}

The $20/share spread on 10,000 shares is a $200,000 bargain element — $45,148 of incremental AMT. It's not lost: the same $45,148 becomes a Minimum Tax Credit to recover in later years when regular tax exceeds tentative minimum tax.

2 · Find the largest $0-AMT exercise

How many shares can they exercise this year without tripping AMT? That's the crossover — /v1/equity-comp/iso-amt-capacity.

curl -X POST https://api.numeratica.com/v1/equity-comp/iso-amt-capacity \
  -H "Authorization: Bearer nmr_sk_test_xxx" \
  -H "Content-Type: application/json" \
  -d '{
    "tax_year": 2026, "filing_status": "single",
    "strike_price": 2, "fmv_at_exercise": 22, "ordinary_income": 200000
  }'

{
  "result_id": "eqc-iso-cap_3b292cebdc4562cb",
  "engine_version": "equity-comp-1.0.0",
  "result": {
    "bargain_element_capacity": 31384,
    "shares_capacity": 1569.2
  },
  "disclaimer": "Calculation engine output for informational purposes only; not tax or financial advice."
}

So 1,569 shares ($31,384 of bargain element) can be exercised at $0 AMT this year. A common play: exercise to the crossover annually to spread the bargain element across tax years and avoid the bill.

3 · Render it

Put the decision in one card.

<div style="font-family:-apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif;max-width:440px;border:1px solid #e6e9ef;border-radius:14px;overflow:hidden;color:#1a2230">
  <div style="background:#eef2ff;padding:16px 20px;border-bottom:1px solid #e6e9ef">
    <span style="display:inline-block;background:#4338ca;color:#fff;font-size:12px;font-weight:700;padding:3px 11px;border-radius:999px;letter-spacing:.04em">ISO · AMT</span>
    <div style="color:#5b6675;font-size:13px;margin-top:12px">AMT if you exercise all 10,000 shares</div>
    <div style="font-size:34px;font-weight:700;color:#4338ca;line-height:1.1">$45,148</div>
  </div>
  <div style="padding:8px 20px 14px;font-size:14px">
    <div style="display:flex;justify-content:space-between;padding:7px 0;border-bottom:1px solid #f1f3f7"><span style="color:#5b6675">Bargain element</span><strong>$200,000</strong></div>
    <div style="display:flex;justify-content:space-between;padding:7px 0;border-bottom:1px solid #f1f3f7"><span style="color:#5b6675">Incremental AMT</span><strong>$45,148</strong></div>
    <div style="display:flex;justify-content:space-between;padding:7px 0;border-bottom:1px solid #f1f3f7"><span style="color:#5b6675">AMT credit carryforward</span><strong>$45,148</strong></div>
    <div style="display:flex;justify-content:space-between;padding:7px 0"><span style="color:#5b6675">$0-AMT exercise capacity</span><strong>1,569 shares</strong></div>
  </div>
  <div style="padding:10px 20px;color:#5b6675;font-size:12px;border-top:1px solid #f1f3f7">Single · $200k income · 2026 · result_id eqc-iso_9a57d8261deaf54a · not tax advice</div>
</div>

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