NSO vs ISO After-Tax Comparison Calculator 2027

Compare Non-Qualified Stock Options (NSOs) vs Incentive Stock Options (ISOs) after-tax outcomes for 2027 — including ordinary income, AMT, and capital gains treatment.

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Tax Treatment Difference

NSO: ordinary income tax + FICA on bargain element at exercise. ISO: NO regular tax at exercise (but AMT preference); capital gains on sale IF held 1 year from exercise AND 2 years from grant (else disqualifying disposition = ordinary).

When ISO Wins

Long-term hold + significant gain + can absorb AMT + low income in exercise year. Long-term capital gains (15-20%) beats ordinary (35-37%) by 15+ points. On $500k gain: ISO long-term wins $75k+ vs NSO.

When NSO Wins (or Ties)

Cash-strapped + no plan to hold (instant sale). Or income hovering near AMT threshold (small exercise won't trigger AMT). NSO is also simpler — no surprise AMT, no holding period traps.

The Disqualifying Disposition Trap

Sell ISO shares within 1 year of exercise or 2 years of grant = disqualifying disposition. ISO treated like NSO retroactively — ordinary income on bargain element. AMT preference reversed but you owe ordinary tax.

Source: irs.gov Section 421-423 ISO/ESPP, Pub 525 NSO tax. Last updated: May 2026.