Tax
Non-Qualified Stock Option (NSO)
A stock option whose spread at exercise is taxed as ordinary W-2 income (with payroll tax) and reported through the employer's paycheck. The default option type at private companies for non-employees and for grants that don't qualify as ISOs.
NSOs (also called NQSOs) are stock options without ISO's special tax treatment. The spread between strike and fair market value at exercise is ordinary income, taxed as W-2 wages with payroll tax withheld.
After exercise, you own the shares. Future appreciation/decline becomes capital gain/loss, measured from the FMV at exercise.
The employer's withholding on an NSO exercise is 22% federal supplemental + FICA + state + Medicare. For a high-earner exercising a large grant, that federal 22% is 13+ points below the actual marginal rate — the balance due at April 15 is often the surprise event of the year. Planning the exercise so the resulting tax bill can be funded without emergency sale of shares is critical, especially for pre-IPO companies where the shares can't easily be sold.
Exercising early — while the FMV is close to the strike price — reduces the ordinary-income spread and starts the long-term capital gains clock (1 year for LTCG). For founders and early employees at pre-IPO companies whose 409A valuation is still low, an early exercise + 83(b) election (where allowed) can convert what would be a large future ordinary-income bill into a small current one, with future appreciation taxed at LTCG rates. Every dollar of pre-exercise appreciation is a dollar avoided at the ordinary-income rate.
For non-employees (board members, advisors, consultants), NSOs are the ONLY option type available — ISOs are limited to employees by statute. Consultant NSO exercises are reported on 1099-NEC (not W-2), and self-employment tax applies to the spread; the tax math is different from employee NSOs.
Common pitfalls
- Default 22% supplemental withholding is too low for high earners, so you'll owe at filing
- Not accounting for cashless exercise mechanics correctly when reconciling 1099-Bs
- Missing the 83(b) election window (30 days after early exercise) — the election converts the ordinary-income spread on future vesting into capital gain instead
- Exercising a large NSO grant near the marginal AMT bracket without modeling AMT — NSO exercise itself doesn't hit AMT preference, but the resulting AGI can push other items into AMT
- Treating consultant NSO exercise like employee NSO — self-employment tax applies to the spread on 1099-NEC reporting
Related service
See personal tax servicesHave a Non-Qualified Stock Option (NSO) situation in your business?
Federal, state, and local returns prepared and reviewed by a licensed CPA, with the planning done before year-end rather than after it.