What Are NSO Stock Options? How Nonqualified Options Work

By Kevin Luu, Co-Founder and Chief Learning Officer. Reviewed on 2026-09-30.

NSO stock options (nonqualified stock options, which the IRS calls nonstatutory options) give you the right to buy a set number of your employer’s shares at a fixed price, the exercise or strike price, for a fixed number of years. They are “nonqualified” because they do not meet the tax code’s rules for incentive stock options, so the gain at exercise is taxed as ordinary wages rather than getting ISO treatment. An NSO is worth something only when the stock trades above your strike price, and it can expire worthless if you leave it too long.

For a two-income household in the Bay Area or Seattle already earning $750k or more, NSOs are rarely a small line item. They are often the largest piece of equity pay that requires a decision from you, because unlike RSUs, nothing happens until you act. This page explains what an NSO is, how one moves from grant to sale, what your options are really worth after tax at your income level, and the decisions that tend to matter most.

What “nonqualified” means, and who gets NSOs

The tax code has two kinds of options with special rules: incentive stock options under Section 422 and options granted under an employee stock purchase plan under Section 423. Any option that does not meet those rules is a nonstatutory option, commonly called an NSO or NQSO (IRS Publication 525). “Nonqualified” says nothing about quality. It only means the option does not get the special ISO tax treatment.

That flexibility is why NSOs are common. ISOs can go only to employees, and only the first $100,000 of stock (valued at the grant date) that becomes exercisable in a calendar year can be treated as ISOs. Anything above that is treated as an NSO (IRC §422(d)). NSOs have no such cap and can also go to directors, advisers and contractors. So a senior scientist or engineer with a large grant often holds both: a slice of ISOs and the rest as NSOs. Your grant agreement and your equity portal state which is which.

How an NSO works, from grant to sale

1. Grant. The company gives you options on a set number of shares at a strike price, usually the stock’s fair market value on the grant date. For a typical employee NSO there is no tax at grant (Pub 525). A strike price set below fair market value can turn the option into deferred compensation under Section 409A, and income included under Section 409A is also subject to an additional 20% tax on top of regular income tax (IRS Instructions for Forms W-2 and W-3). That is why companies set strikes carefully.
2. Vesting. You earn the right to exercise over time, on the schedule in your grant. Vesting itself is not a taxable event for an NSO, unlike an RSU, which is taxed as wages when shares are delivered.
3. Exercise. You pay the strike price and receive shares. The spread (market value minus strike price) is taxed as wages in that year, on your W-2, with federal income tax, Social Security (up to the annual wage base), Medicare and, in California, state income tax and SDI.
4. Sale. Your basis in the shares is what you paid plus the spread already taxed. Any change after exercise is a capital gain or loss, long-term if you held the shares more than one year after exercise. Your holding period starts the day after you exercise (Pub 525; IRS Topic 409).
5. Expiration. Every option has a final date, set in the plan and grant agreement. Leaving the company usually shortens it sharply. An in-the-money option that is not exercised by its deadline is simply lost.

Two practical details catch families. First, at a private company some plans allow early exercise of unvested options; the shares you receive are restricted stock, and a Section 83(b) election must be filed with the IRS no later than 30 days after the shares are transferred to be taxed at exercise instead of at vesting. Second, for options granted on or after January 1, 2014, the basis your broker reports on Form 1099-B leaves out the spread you already paid tax on, so the sale needs an adjustment on Form 8949 or the same income is taxed twice (Pub 525).

NSO vs ISO vs RSU at a glance

The ISO column hides a cost: to keep ISO treatment, shares must be held two years from grant and one year from exercise, and ISOs must be exercised within three months of leaving employment (Pub 525). NSOs have none of those clocks, which makes them simpler to plan, though usually more expensive in tax.

Worked example: what a vested NSO grant is really worth

Assumptions (illustrative): a married couple filing jointly with two children under 10. One spouse is a director at a public biotech in South San Francisco and holds 9,000 vested NSOs with a $30 strike; the stock is at $75. Household taxable income before any exercise is about $1,050,000, so the spread lands in the federal 37% bracket, which starts at $768,700 of taxable income for married couples for 2026 (Rev. Proc. 2025-32). California figures use the 2025 rate schedule, because the Franchise Tax Board had not published 2026 brackets at the time of writing; the spread sits in the 11.3% bracket (up to $1,485,906) and above the $1,000,000 line for the 1% Behavioral Health Services Tax (FTB 2025 rate schedules).

The spread is 9,000 x ($75 minus $30) = $405,000. The screen in your equity portal will often show that number as your “value”. The after-tax number is smaller.

Medicare is 1.45% with no wage cap, plus the 0.9% Additional Medicare Tax on joint wages over $250,000 for 2026; Social Security is already maxed out by salary at the $184,500 wage base (IRS Publication 15 (2026); IRS Additional Medicare Tax Q&A). California SDI is 1.3% of all wages with no cap for 2026 (EDD). Washington has no individual income tax for 2026 (WA DOR); the WA Cares premium is 0.58% of wages for employees who are not exempt (WA Cares Fund).

Now the cash. To exercise and keep all 9,000 shares, the California family needs the $270,000 strike cost plus $214,448 of tax: about $484,448 to own shares worth $675,000 that day. If they sell at exercise instead, they keep about $190,552 in cash and own no shares. Most families land somewhere in between, and the employer’s withholding usually covers only part of the tax. For 2026 many employers withhold federal tax on supplemental wages at the optional 22% flat rate (37% is mandatory once an employee’s supplemental wages pass $1,000,000 in the calendar year), so at a 37% marginal rate the rest is typically due with estimates or at filing (Pub 15).

A Washington caution: the state enacted a 9.9% income tax on adjusted gross income over $1,000,000, effective January 1, 2028 (WA DOR). Guidance is still pending, but a large exercise in 2028 or later may be caught by it, so the year you exercise long-dated NSOs is a real choice.

The decisions NSO holders actually face

When to exercise

Because the spread is taxed as wages whenever you exercise, holding unexercised NSOs is a bet on the stock with no tax saving built in, unlike ISOs. For a household already in the top federal bracket, there is rarely a “lower-income year” to wait for, unless a sabbatical or a parental leave year is genuinely planned. A move to Washington does not erase California tax on the spread: if you exercise after becoming a nonresident, California still taxes the share of the spread tied to your California workdays between grant and exercise (FTB Publication 1004). Waiting does keep your cash free and limits loss if the stock falls, since an option cannot be worth less than zero.

Exercise and hold, or exercise and sell

Holding after exercise starts the one-year clock for long-term gain treatment. In California that changes little, because the state taxes capital gains as ordinary income (FTB). Federally, a gain on shares held more than one year is taxed at up to 20% for 2026 instead of ordinary rates of up to 37%, and at this income level the 3.8% net investment income tax applies to the gain either way (Rev. Proc. 2025-32; IRS NIIT). In Washington, the spread itself is wages and not subject to the state capital gains tax, but a later long-term gain on the shares can be: 7% on gains above the annual standard deduction ($278,000 for 2025, the latest published figure) and 9.9% on taxable gains above $1,000,000 (WA DOR). Weigh that against the risk of adding even more of your employer’s stock to a household that already depends on it for salary and RSUs. The mechanics of selling at exercise are covered in our guides to cashless exercise and sell to cover versus same-day sale.

Leaving the company, or the company being sold

Leaving usually starts a short post-termination exercise window set by your plan; some companies give much longer. Read the grant agreement before you resign, because unexercised in-the-money options lost at that deadline are a common and avoidable loss. In an acquisition, NSOs may be cashed out, converted into the buyer’s options or accelerated, depending on the deal terms (see what happens to your stock when a company sells). At private companies, a tender offer may be your only chance to sell before an exit.

A five-question NSO checklist

1. How many options are vested, at what strike, and what is the final exercise date for each grant?
2. Which grants are NSOs and which are ISOs?
3. What is the after-tax value at today’s price, using your real marginal rate, not the portal number?
4. How much of your household net worth is already in this one stock through RSUs, ESPP and options?
5. What is the exercise window if you leave, and does your plan allow cashless exercise?

What to write down for your kids

Your children will not remember which grant you exercised in which year. They can learn why you chose to sell, hold or wait, and how you weighed the risk of owning too much of one company. A one-page note after each large exercise, with the price, the tax, the reason and what you would do differently, becomes part of your family’s FamilyKnowledge® Library. As Kevin Luu, co-founder of Bright Advisers, puts it: “Your kids don’t need to inherit your portfolio. They need to inherit your decision-making process.”

Frequently asked questions

What does NSO stand for?

NSO stands for nonqualified stock option, also written NQSO. The IRS uses the term nonstatutory stock option. All three mean the same thing: an option to buy company stock at a fixed price that does not meet the Section 422 rules for incentive stock options, so the spread at exercise is taxed as ordinary wage income in the year you exercise.

Do NSOs trigger the alternative minimum tax?

No. Exercising an NSO does not create an AMT adjustment, because the spread is already fully taxed as regular income. AMT is an ISO issue: the spread on ISOs exercised and held past year end counts as AMT income. If you hold both kinds, the order and timing of exercises can matter, which is a reason to plan them together.

Are NSOs better or worse than RSUs?

Neither by default. At the same grant value, an RSU keeps value if the stock falls, while an NSO loses value faster and can become worthless below the strike. NSOs give more upside if the stock rises sharply and let you choose when to be taxed. RSUs are taxed at vest whether or not you want the income that year.

Next step

Pull your grant summary from your equity portal and list every NSO grant with its strike price and expiration date, then run the after-tax math above at your own marginal rate. If you want a second set of eyes on the timing, our tax management and investment risk management work covers exactly this decision, and the Tax & Wealth Assessment is the place to start.

This is general education, and the right move depends on your family’s full picture.

Written by

Kevin Luu

Co-Founder and Chief Learning Officer, Bright Advisers

Kevin has advised high-income W-2 tech and biotech families since 2015, and leads the education-first Age Five Family Office from Brea, California.

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