The two option types in one minute
A stock option gives you the right to buy company shares at a fixed "strike" price. Incentive stock options (ISOs) receive favorable tax treatment but come with alternative-minimum-tax complexity. Non-qualified stock options (NQSOs) are simpler and more common, but the gain at exercise is taxed as ordinary income. The difference in when and how you're taxed drives almost every decision that follows.
How NQSOs are taxed
When you exercise an NQSO, the "spread" — the market price minus your strike price — is treated as ordinary compensation income. It appears on your W-2, is subject to income tax and payroll (FICA) tax, and is typically withheld at exercise. From that point, the shares have a cost basis equal to the market price at exercise, and any further gain or loss when you sell is a capital gain or loss.
Example: you exercise 1,000 NQSOs with a $10 strike when the stock is $60. The $50,000 spread is ordinary income now. If you later sell at $80, the additional $20,000 is a capital gain — long-term if you held the shares more than a year after exercise.
How ISOs are taxed
ISOs are the tax-advantaged cousin. When you exercise and hold, there is no regular federal income tax at exercise. If you then meet the holding-period rules, your entire gain — from strike price to sale price — can be taxed at long-term capital-gains rates rather than ordinary rates. That's the prize.
The catch: the AMT trap
There's a significant caveat. When you exercise ISOs and hold the shares past year-end, the bargain element (market price minus strike at exercise) becomes a preference item for the alternative minimum tax (AMT). In other words, you can owe AMT on a paper gain even though you sold nothing and received no cash. If the stock then falls, you may have paid tax on value that evaporated. This is the single most common — and most painful — ISO mistake, and it's entirely avoidable with planning.
The $100,000 ISO limit
Only $100,000 of ISOs (measured by grant-date value) can become first exercisable in any single year. Anything above that is automatically treated as an NQSO. It's a rule that quietly reclassifies part of a large grant, so it's worth checking before you plan an exercise.
Qualifying vs. disqualifying dispositions
To capture the full ISO benefit, you must make a qualifying disposition: sell more than two years after the grant date and more than one year after exercise. Meet both and the entire gain is long-term capital gain. Miss either — a disqualifying disposition — and part of the gain is recharacterized as ordinary income. Sometimes a disqualifying disposition is the right move (for example, to avoid AMT), but it should be a deliberate choice, not an accident.
| ISOs | NQSOs | |
|---|---|---|
| Tax at exercise | None for regular tax; bargain element is an AMT item | Ordinary income on the spread (on your W-2) |
| Payroll tax (FICA) | No | Yes |
| Best-case rate on gain | All long-term capital gain (if holding periods met) | Ordinary at exercise, then LTCG on later gain |
| Holding period for best case | 2 yrs from grant + 1 yr from exercise | 1 yr from exercise for LTCG on post-exercise gain |
| Main watch-out | AMT on exercise-and-hold | Under-withholding at exercise |
The exercise-and-hold decision
Deciding whether to exercise and hold ISOs is a balance: the reward is converting ordinary income into lower-taxed capital gain, and the costs are the cash to exercise, the AMT exposure, and the concentration risk of holding more company stock. There's no universal answer — it depends on your other income, your AMT position, how much of your net worth is already in the stock, and your conviction about the company.
When to exercise: timing frameworks
- Exercise early in the year. If you exercise-and-hold in January, you have until December to see how the stock moves — and can sell before year-end (a disqualifying disposition) to unwind the AMT exposure if it drops.
- Exercise up to your AMT crossover. There's often an amount you can exercise each year before AMT kicks in. Filling that space annually spreads the benefit across years.
- Coordinate with your whole tax picture. RSU vesting, bonuses, and NQSO exercises all stack. The right ISO move depends on everything else happening that year.
Related reading: RSUs and the under-withholding trap, and our equity compensation planning service.
Disclosure: Skyview Financial Group, LLC is an SEC-registered investment adviser (CRD #310581). This article is educational only and is not individualized tax, legal, or investment advice. AMT rules, thresholds, and rates are current as of August 2026 and subject to change; please consult your CPA. Examples are illustrative and do not reflect any specific client.