NSO tax refers to the tax treatment of non-qualified stock options — primarily ordinary income on the bargain element at exercise, distinct from capital gains treatment on later sale.

How it works

You exercise 10,000 NSOs at $1 strike when FMV is $11. Spread = $10 × 10,000 = $100,000 compensation income reported on W-2, subject to federal/state income tax and payroll taxes (Social Security and Medicare up to applicable limits). When you later sell shares, additional gain or loss may qualify as capital gains depending on sale price versus FMV at exercise.

Employers typically withhold taxes via cash payment, share withholding, or sell-to-cover on available liquidity events. Private companies without tenders leave employees to fund taxes from savings or external loans.

Contrast with ISOs: ISO exercise may avoid ordinary income at exercise if AMT and holding rules are satisfied — NSOs do not offer that preference.

Why it matters

• Founders: Equity compensation is recruiting currency; educate hires on NSO tax before grant acceptance. Liquidity programs and extended exercise windows reduce forced bad-timing exercises.
• Investors: Cap table and retention diligence includes whether key talent faces large underwater or highly taxable exercises that affect departure risk.

Common mistake

Exercising NSOs early in a private company expecting tax only at IPO. Tax is due at exercise; IPO timing does not defer NSO wage income.

Related ideas

See also NSO, ISO and AMT, sell-to-cover withholding, and equity incentive plan.