What Is Early Exercise of Stock Options? Definition and Examples

A stock option is the right to buy shares at a fixed exercise price. Most options vest over time, often over four years. You usually cannot exercise an option until the shares vest. With early exercise, the plan lets you buy all the shares from the start, whether they are vested or not.

Shares you buy early are still unvested. The company keeps a right to repurchase the unvested ones if you leave. The option agreement sets the buyback price, so check whether it is the price you paid or the current value. As you keep working, the shares vest on the original schedule and the buyback right shrinks.

Only some companies offer this feature, and it must be written into your plan. It is more common at young private companies, where the exercise price is low. The price is often set from a 409A valuation, an independent appraisal of the common stock. See how to exercise stock options for the standard process.

The tax code treats unvested shares as property you could lose. Under Section 83, you are taxed on the value of such shares, minus what you paid, only when they stop being at risk. That means when they vest. If the shares have risen in value by then, the gain is taxed as income at each vesting date.

The Section 83(b) election changes the timing. You choose to be taxed when you buy the shares instead. If the shares are worth what you paid, the amount is zero. The tax code requires the election within 30 days after the transfer. The IRS says you can make it with a written statement or with Form 15620. You also give a copy to your employer.

Two benefits follow. First, later growth is not taxed as pay. Second, your holding period starts at the purchase date. Under the Treasury regulation, the period begins just after the transfer when you make the election, and just after vesting when you do not. A sale more than one year after the purchase can then qualify for the long-term capital gains rate. See cost basis for how your basis is set.

An incentive stock option (ISO) has special tax treatment. You generally owe no regular income tax when you exercise. You may owe the alternative minimum tax (AMT), a second tax calculation, in the year you exercise. The IRS says this on its stock options page. Your company then sends you Form 3921 to record the exercise.

For AMT, the tax code switches off the ISO exclusion in Section 56(b)(3). So an early-exercised ISO can be treated like other unvested stock for AMT. An 83(b) election can then set the year in which the spread, the gap between share value and your price, counts. Because the rules interact, ask a tax adviser before you early exercise an ISO.

ISOs also have a size cap. Stock whose total value at grant is above $100,000 and first becomes exercisable in one calendar year stops being an ISO for the excess. The rest is taxed like a non-qualified option. To get the ISO treatment, you must also hold the shares two years from the grant and one year from the exercise. See ISO vs NSO and AMT.

An employee has 40,000 non-qualified options at a $1 exercise price. They vest over four years at 10,000 shares a year. The shares are worth $1 today. The company later lists, and the employee sells everything at $16 a share. Along the way, the value is $2, $4, $8 and $16 when each yearly block vests.

The total profit is $600,000 either way. With early exercise, all of it is capital gain, because the 83(b) amount was zero. When the employee exercises as shares vest, $260,000 is taxed as income at the time and $340,000 as capital gain. The cost is paying $40,000 up front and carrying the risk for four years.

• Missing the 30-day deadlineThe deadline is set by the tax code. If you miss it, you are taxed at each vesting date on the value then.
• Paying for shares that never vestIf you leave, the company may buy back unvested shares. The loss you can claim is what you paid minus what you get back.
• Exercising when the shares are worth more than the priceThe gap is taxed as income when you elect, even though you hold no cash from a sale. Check the value against your exercise price first.
• Putting in cash you cannot sparePrivate shares are hard to sell. The company may never list, and the money can be lost entirely.
• Ignoring AMT on ISOsAn early-exercised ISO can raise your AMT bill in the year you exercise. Ask an adviser to run the numbers.

Early exercise

Buying the shares under an option before they vest. The company keeps a right to buy back unvested shares if you leave.

Vesting

Earning the right to keep your shares over time, often over four years.

Exercise price

The fixed price per share you pay to buy shares under the option.

Section 83(b) election

A choice, made within 30 days of buying unvested shares, to be taxed on their value at purchase.

Incentive stock option (ISO)

An option that can avoid regular income tax at exercise if holding and size rules are met.

Alternative minimum tax (AMT)

A second tax calculation that can apply in the year you exercise an ISO.

Spread

The gap between the value of a share and your exercise price.

Figures were last checked on October 13, 2026. Rules are US federal. The worked example is illustrative arithmetic. State taxes are not covered.