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The Global Insight

Are ISOs taxable upon exercise?

Author

Christopher Davis

Updated on March 09, 2026

However, unlike NSOs or even RSUs, the main benefit of ISOs is the way they’re taxed. NSOs are considered wages, so income tax and FICA taxes are withheld when you exercise your options. That’s not the case with ISOs. Additionally, ISOs have the potential to yield preferential tax treatment.

Do you pay taxes on ISOs?

ISOs are taxed in two ways. The first method is on the spread, and the second is on any increase (or decrease) in the stock’s value when it disposed of or sold. 2 The income from ISOs is subject to regular income tax and alternative minimum tax, but it is not taxed for Social Security and Medicare purposes.

Are ISOs tax deductible?

Employers generally are not allowed tax deductions for ISOs, and ISO plans are less flexible and more difficult to administer. For these reasons, ISOs are most commonly used by start-up companies that do not yet have taxable income and that have the potential for substantial appreciation in their stock price.

Does exercising options create a taxable event?

ISOs are usually seen as more advantageous for the employee, in part because the exercise date isn’t a taxable event (though higher-earning employees have to make an alternative minimum tax, or AMT, adjustment based on the difference between the current market price and the exercise price).

When should I exercise ISOs?

It is often recommended to exercise ISOs in January in order to give yourself time to amass cash from January to December to pay the AMT the following year. If your sole priority is minimizing AMT, you should sell your shares in the same year as you exercise your options.

What happens when I exercise an ISO?

When you exercise Incentive Stock Options, you buy the stock at a pre-established price, which could be well below actual market value. The advantage of an ISO is you do not have to report income when you receive a stock option grant or when you exercise that option.

Is NSO better than ISO?

An ISO Leads to a Lesser Tax Liability With an NSO the difference between the exercise price and the fair market value of the stock is considered ordinary income. The tax treatment of an ISO often results in less taxes because there are no taxes owed on the spread at the time of exercise.

Should I exercise ISOs or NSOs?

Only employees can receive ISOs, whereas NSOs may be granted to any service providers (e.g., employees, directors, consultants, and advisors). ISOs must be exercised within three months following termination of employment (even if the holder continues providing services in some other capacity).

What are the tax consequences of exercising an ISO?

With ISOs, at exercise or later sale you have no withholding at all and no Social Security or Medicare tax. Beyond the question of whether your exercise triggers the AMT, meeting the holding-period requirements of an ISO can result in substantially lower taxes. Example: Your exercise price…

What does it mean when you exercise an ISO?

You merely purchased the stock, and your cost basis is the strike price. However, for AMT purposes, the difference between what you paid and what the stock is worth at the time of exercise is a “preference item” for AMT. What that means is that amount is added to your income for the AMT calculation.

What are the tax implications of exercising options early?

Disadvantages of exercising options early: to exercise your options, you must pay (S * N) + (F – S) (N) (income tax or AMT rate) where S = strike price, F = fair market value, N = number of shares. This may be a lot of money up front, especially given that you might not actually be able to sell these options for a long time.

What happens when you exercise an incentive stock option?

When you exercise and hold an Incentive Stock Option (ISO) there is no taxable event for ordinary tax. You merely purchased the stock, and your cost basis is the strike price. However, for AMT purposes, the difference between what you paid and what the stock is worth at the time of exercise is a “preference item” for AMT.