Post-Termination Exercise Window: 6 Things to Settle First

Post-Termination Exercise Window: 6 Things to Settle First

Your post-termination exercise window is the period after your last day of work during which you can still buy the shares your vested options give you. When it closes, the options generally expire, and vested options you spent years earning can be worth nothing. For many plans the window is 90 days. The clock does not wait for a severance negotiation or a job search.

Here are six things to settle first, in the order that makes the decision easiest. The numbering is a sequence, not a ranking. One firm to ask about the tax side is Doug Johnson CPA, a Los Angeles firm whose live profile lists Equity Compensation as a specialty. Doug Johnson CPA is a vetted Sam's List member and a paying member of our featured program; payment does not buy the language we use or its reviews. How we chose is at the end.

1. Find Your Post-Termination Exercise Window and the Option Expiration Date

Start with the documents, not with what a colleague told you. The deadline lives in your option grant agreement and the company's equity plan. Find two dates: the end of your post-termination exercise window, and the option expiration date, which is the outer limit of the option's life, commonly ten years from the grant.

The two are different. If you leave in year three of a ten-year option, your window may still end 90 days after your last day, even though the option itself had seven years to run. The shorter date controls.

Also check what counts as your termination date. It may be your last day worked, the end of a notice period or the end of a garden-leave arrangement. Ask the company's equity administrator for the date in writing, and ask when the clock starts.

The limitation: plans differ, and a few give longer windows for disability or death. Do not assume yours matches a typical 90-day plan, and do not rely on a verbal answer from a manager.

2. Check Whether the ISO 90 Day Rule Applies to You

If your options are incentive stock options, the law generally requires you to exercise within three months of leaving to keep incentive stock option treatment. That is the ISO 90 day rule. After three months, an incentive stock option that is exercised is generally taxed as if it were a nonstatutory option.

The difference is real. An incentive stock option exercised on time can avoid regular income tax at exercise, though the spread may be counted for the alternative minimum tax. A nonstatutory option exercised later generally creates ordinary income on the spread in the year you exercise, usually reported as wages, even for a former employee.

So an exercise on day 91 can cost more than an exercise on day 89, even though the shares are the same. Check your grant to see which type of option you hold. Many people hold some of each.

The limitation: the test is three calendar months, which is not always exactly 90 days, and there are different rules for disability, and the $100,000 limit on incentive stock options first becoming exercisable in a year can turn part of a grant into nonstatutory options from the start. Your records should say which is which.

3. Work Out the Cash Needed to Exercise

Exercising an option means paying the exercise price for every share you buy. For a large grant, that number can be bigger than people expect. Ten thousand options at an exercise price of $4 cost $40,000 to exercise, before any tax.

Then add tax. On a nonstatutory option, the tax is on the spread between the share's fair market value and your exercise price, and it is due as ordinary income. On an incentive stock option, the regular tax may be deferred, but the alternative minimum tax can apply. In both cases, you may owe cash on a gain that exists only on paper.

Put the three numbers side by side: the exercise price, the expected tax and the cash you have. Some people exercise only part of the grant for this reason, and let the rest expire.

The limitation: exercising spends cash on shares that may never be worth more than you paid. If the company's value falls, the exercise price is gone and so is any tax paid, though a later loss may be limited.

4. Estimate the Tax Before the Post-Termination Exercise Window Closes

Run the numbers while there is still time to choose. A tax professional can model the regular tax and the alternative minimum tax side by side for different exercise sizes, and show how much of the grant fits under a number you can pay.

Here is the illustrative shape, with invented numbers. An employee leaves holding 20,000 vested nonstatutory options with an exercise price of $3, in a company whose current fair market value is $11. The spread is $8 per share, so exercising all of them creates $160,000 of ordinary income, in addition to the $60,000 exercise price. Exercising half creates $80,000 of income and costs $30,000 in exercise price.

Withholding is also part of the picture. For a former employee, the company may withhold tax from the exercise, and the withholding may not be enough for the actual bill.

The limitation: the figures above are illustrative, not a calculation. Your actual tax depends on your other income, your filing status, your state and the value the company assigns to the shares, and you should model it before you exercise, not after.

5. Ask What Happens to the Shares if the Company Is Private

If the company is public, you can often sell shares right after you exercise and use the proceeds to pay the cost. If it is private, there may be no market. You could pay to exercise, owe tax on the spread and hold shares you cannot sell.

Ask what the company's rights are. Some private companies keep a right to buy back shares from former employees, sometimes at a price below what you paid. Some restrict transfers. Some only let you sell during a tender offer, which may be a year or more away or may never happen.

Also ask what the current value is based on. A valuation for tax purposes, often a 409A valuation, can differ from the price investors paid. The tax is generally based on the former, but your decision is probably based on the latter.

The limitation: illiquid shares are a risk, not only a tax question. A person who exercises everything and cannot sell any of it can owe more in tax than the shares are ever worth in cash.

6. Ask Whether the Window Can Be Extended

Some companies extend the post-termination exercise window to a year or longer, or offer an extension at departure. It is a plan feature, a negotiated term or a company policy, so it is worth asking in writing, before the window starts running down.

An extension is not free of tax consequences. For an incentive stock option, extending the exercise period can be treated as a modification, which can change its tax status. That may be acceptable, but you should know it before signing an amendment.

If you are negotiating severance, the exercise window is one of the terms that has real value, and it is easier to negotiate before you sign than after.

Doug Johnson CPA is based in Los Angeles, founded in 2024, with three employees, serving clients nationwide. Its live profile positions the firm for growing businesses in the $250,000 to $10 million revenue range and for high earners with equity compensation, and lists SMB Owners, Equity Compensation, High Net Worth Individuals and Growing Companies as specialties.

Doug Johnson CPA has 15 verified client reviews on Sam's List. Each review is submitted by an individual who identifies as a client of the firm and rates it on communication, subject-matter knowledge, and overall satisfaction. Reviews reflect those individual experiences and do not represent an endorsement by Sam's List. Doug Johnson CPA is a paying member of our featured program, and payment does not buy its reviews. Ratings and rankings are not indicative of future performance or results.

The limitation, plainly: the profile lists minimums of $250,000 in income and $250,000 in revenue, so a person with a smaller income may fall outside them. It does not say how the firm prices a one-time modeling project, so ask whether it will do one on a deadline.

Frequently Asked Questions

What is a post-termination exercise window?

It is the period after you leave a company during which you can still exercise vested stock options. For many plans it is 90 days, and when it ends the options generally expire. Your grant agreement and the equity plan state the exact date.

What is the ISO 90 day rule?

To keep incentive stock option tax treatment, you generally must exercise within three months of leaving. Exercise later and the option is generally taxed like a nonstatutory option, with ordinary income on the spread. Disability has a longer period, so check your facts.

Can I lose my options if I miss the window?

Generally yes. When the post-termination exercise window closes, unexercised vested options usually expire and cannot be revived. Some companies extend the window, but only if the plan or an agreement allows it, so ask early and get it in writing.

Do I owe tax when I exercise options after leaving?

It depends on the option type. A nonstatutory option generally creates ordinary income on the spread when you exercise. An incentive stock option may avoid regular tax at exercise but can trigger the alternative minimum tax. Model both before you act.

Before the window closes, list each grant with its type, exercise price, vested count and deadline. You can browse accountants on Sam's List, including the firm above, and ask each one how it models an exercise on a deadline.

How We Chose This Firm

You should be able to check our work, so here is how this post was built.

The pool. The firm here is a vetted Sam's List member in our featured program with a live public profile that lists Equity Compensation as a specialty. This is not a survey of every CPA who handles stock options, and many Sam's List members not written up here could fit.

How it is organized. The six items are a sequence to work through, not a ranking. One firm is written up, so there is no order of firms.

What review counts mean here. We cite the firm's verified review count and its date from its profile. A count shows how many clients wrote something down. It does not measure technical quality.

What payment does and does not buy. Listing on Sam's List is free, and so is being named in this article. The firm written up here is a paying member of our featured program, which is why it gets a write-up. What payment does not buy is the language we use about a firm, its review count, or a promise that it fits you.

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About the author: Kimberly Green is the cofounder of Sam's List, where business owners and high earners find vetted CPAs, financial advisors, and fractional CFOs. She's met one-on-one with 400+ financial professionals and writes from the real data behind thousands of client-advisor matches. Ask her anything about finding an accountant - she's heard it all, including the questions people are afraid to ask.