Yes, stock options are taxable, but when the tax hits and at what rate depends on which kind you hold. Non-qualified stock options (NSOs) create ordinary income the moment you exercise them. Incentive stock options (ISOs) generally defer tax until you sell, and if you meet the holding rules, the entire profit is taxed at long-term capital gains rates. Both types can generate capital gains at sale, and a handful of other taxes — the Alternative Minimum Tax, the Net Investment Income Tax, and state income tax — can layer on top.
How NSOs Are Taxed
NSOs are the most common form of equity compensation and can be issued to employees, contractors, and board members. The grant itself usually isn’t a taxable event because the option’s value isn’t fixed or transferable yet.1Office of the Law Revision Counsel. 26 USC 83 – Property Transferred in Connection With Performance of Services Tax arrives when you exercise.
The taxable amount is the spread: the fair market value of the stock on the exercise date minus the strike price you paid. Exercise 500 shares at a $20 strike when the stock trades at $60, and you have $20,000 of ordinary income. That income can be taxed at rates up to 37% federally.2Internal Revenue Service. Federal Income Tax Rates and Brackets
Payroll taxes apply to the spread as well. Social Security tax of 6.2% applies up to the annual wage base of $184,500 in 2026, so if your salary already exceeds that cap, little or none of the spread is hit.3Social Security Administration. Contribution and Benefit Base Medicare tax of 1.45% applies to the full spread with no cap, and an additional 0.9% Medicare surtax kicks in once your total earnings pass $200,000.4Internal Revenue Service. Topic No. 751, Social Security and Medicare Withholding Rates These taxes are due at exercise even if you never sell the shares. Any additional gain between the exercise date and the eventual sale is a capital gain.
How ISOs Are Taxed
ISOs are available only to employees and offer a more favorable structure. A qualifying ISO exercise produces no regular income tax on the spread at that time.5Office of the Law Revision Counsel. 26 USC 421 – General Rules You can pick up shares without an immediate federal income tax bill on the paper gain.
The payoff comes at sale. If you meet the ISO holding periods, your full profit from the strike price to the sale price is taxed at long-term capital gains rates, generally 15% or 20% depending on income.6Internal Revenue Service. Topic No. 409, Capital Gains and Losses Compare that to the 37% ceiling on ordinary income and the difference is substantial.
There is a cap. Only $100,000 worth of ISOs — measured by the stock’s fair market value on the grant date — can become exercisable for the first time in any calendar year. Options above that ceiling are treated as NSOs for tax purposes.7Office of the Law Revision Counsel. 26 USC 422 – Incentive Stock Options
Holding Periods That Set Your Rate
NSOs
For NSOs, the capital gains clock starts on the exercise date. Hold the shares more than a year and any gain above the exercise-date value is a long-term capital gain.6Internal Revenue Service. Topic No. 409, Capital Gains and Losses Sell inside a year and that gain is taxed as ordinary income. The spread at exercise is always ordinary income no matter how long you hold afterward.
ISOs
ISOs impose two clocks at once. You must hold the shares at least two years from the grant date and at least one year from the exercise date.7Office of the Law Revision Counsel. 26 USC 422 – Incentive Stock Options Miss either and you have a disqualifying disposition: the spread at exercise becomes ordinary income, and any further gain is a capital gain, short- or long-term based on how long you held after exercise. The net effect is that a disqualifying disposition strips the ISO benefit off the spread and taxes it the way an NSO would have been.
The AMT Trap on ISO Exercise
ISOs escape regular income tax at exercise, but not the Alternative Minimum Tax. For AMT purposes, the law removes the ISO exclusion and adds the spread back into your income for the parallel calculation.8Office of the Law Revision Counsel. 26 USC 56 – Adjustments in Computing Alternative Minimum Taxable Income You compute your tax both ways and pay the higher figure.
That can produce a real bill in a year you haven’t sold anything and haven’t seen any cash. The AMT exemption for tax year 2026 is $90,100 for single filers and $140,200 for joint filers, with AMT rates of 26% or 28% on income above the exemption.9Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026
AMT paid on an ISO exercise isn’t necessarily gone. You can claim a minimum tax credit on Form 8801 in later years when your regular tax exceeds your AMT, and the credit carries forward indefinitely.10Internal Revenue Service. Instructions for Form 8801 Recovering the full credit takes careful records of the exercise year and the AMT paid.
Leaving Your Employer Starts a Clock
Quitting, being laid off, or otherwise separating starts a countdown on any ISOs you hold. To keep ISO tax treatment, you generally have to exercise within three months of your last day. The window extends to one year if you’re disabled.11Office of the Law Revision Counsel. 26 USC 422 – Incentive Stock Options Exercise later and the option automatically becomes an NSO, so the spread turns into ordinary income subject to income and payroll taxes.
Your option agreement may set a shorter window or a longer one. A longer window doesn’t override the tax rule: past three months, ISO status is lost regardless of what the plan document allows. NSOs have no statutory deadline, but plans typically set their own window, and unexercised options expire worthless once it closes.
Section 83(b) Election for Early Exercise
Some plans let you exercise unvested shares. If yours does, a Section 83(b) election lets you recognize the spread as income at the transfer date rather than waiting for each tranche to vest.1Office of the Law Revision Counsel. 26 USC 83 – Property Transferred in Connection With Performance of Services If the stock climbs between transfer and vesting, that increase becomes capital gain instead of ordinary income.
The deadline is unforgiving. The election must reach the IRS within 30 days of the transfer, and it can’t be revoked once filed.12Internal Revenue Service. Form 15620, Section 83(b) Election Instructions The risk is that if you leave before the shares vest and forfeit them, you don’t get back the tax you already paid.
Section 409A and Private Company Options
Options from a private company carry a specific hazard. If the strike price is set below the stock’s fair market value at grant, the options can be recharacterized as deferred compensation under Section 409A. The consequences: immediate income inclusion, an additional 20% tax on the deferred amount, and interest at the IRS underpayment rate plus one percentage point back to the year the compensation was first deferred.13Office of the Law Revision Counsel. 26 USC 409A – Inclusion in Gross Income of Deferred Compensation Under Nonqualified Deferred Compensation Plans
Companies avoid this by getting an independent 409A valuation before granting options, usually refreshed at least every 12 months or after events like a new funding round. The penalties for mispricing land on you, not the company, so it’s fair to ask whether a recent 409A valuation was done before you accept a grant.
Net Investment Income Tax
Higher earners face an extra 3.8% Net Investment Income Tax on gains from selling option stock. It applies to the lesser of your net investment income or the amount your modified adjusted gross income exceeds $200,000 for single filers, $250,000 for joint filers.14Internal Revenue Service. Topic No. 559, Net Investment Income Tax Stacked on the 20% long-term capital gains rate, the effective federal rate on those gains reaches 23.8%.
State Income Tax
Federal rules are only half the calculation. Most states tax stock option income, and their treatment varies widely. Some states impose no individual income tax; top marginal rates elsewhere exceed 13%. A few states tax capital gains at lower rates than ordinary income, but most do not. State tax can apply at exercise, at sale, or both, and moving between states while holding the options complicates things further. For any grant of meaningful size, checking your state’s specific rules is worth the effort.
Reporting and the Double-Tax Trap
NSO spreads show up on your W-2, with the amount separately identified in Box 12 under Code V and already included in your Box 1 wages. For ISOs, your employer files Form 3921 reporting the strike price, exercise-date fair market value, and exercise date — figures you’ll need for both the regular return and any AMT calculation.15Internal Revenue Service. About Form 3921, Exercise of an Incentive Stock Option Under Section 422(b) Employee stock purchase plan transfers are documented on Form 3922.16Internal Revenue Service. About Form 3922, Transfer of Stock Acquired Through an Employee Stock Purchase Plan
Sales get reported on Form 8949 and Schedule D. Watch the cost basis carefully. For NSOs, the basis reported on the brokerage’s Form 1099-B often omits the spread you already paid tax on at exercise. If you don’t adjust the basis up by the amount reported as W-2 income, you’ll pay tax on the same money twice.17Internal Revenue Service. Instructions for Form 8949 The grant and exercise dates on Forms 3921 and W-2 also confirm whether you’ve cleared the holding-period thresholds. Pulling those documents together before you start the return prevents the most expensive filing mistakes.