Stock Option Post-Termination Exercise
Final day to exercise vested options after leaving — measured in NYSE/NASDAQ trading days.
These calculators are for informational purposes only and do not constitute legal, financial, or professional advice.
How the Stock Option Post-Termination Exercise works
The Stock Option Post-Termination Exercise calculator takes the date you leave a company and the length of your plan's exercise window and returns the last day you can still exercise your vested options. Enter your separation date and the number of days your equity plan specifies — commonly 90 — and the tool counts forward, skipping weekends and the market holidays of the calendars you select, so the result is a day you can actually transact on.
The clock starts on your termination or separation date, not the day you announced you were leaving or your last day physically in the office. That single anchor governs everything downstream, so fix it from your separation agreement first. Vesting only decides what you are allowed to exercise; leaving the company starts a separate, much shorter clock against everything already vested, and once it expires the options are gone for good.
This tool measures the window in NYSE/NASDAQ trading days, which is why it removes market holidays as it counts. Plans usually state the window in calendar days, so set the day count and the holiday calendar to match how yours is written — and read the result as the last day you can realistically click "exercise," not a date to race, since funding the strike price and any tax takes time of its own.
Worked example
Suppose your last day of service is Friday, October 2, and your plan gives a 90-day exercise window. Counted as 90 calendar days the window would end around New Year's — but if that day lands on a weekend or a market holiday you cannot transact, and the calculator instead shows you the nearest open trading day so you are not blindsided. Change the window to the 60 days some plans use, and the deadline pulls forward by a month from the same separation date.
Frequently asked questions
What date does the exercise window start from?
From your termination or separation date as defined in your equity plan and separation agreement — not the day you gave notice or your last day in the office. If a notice period or garden leave is involved, confirm whether your service is treated as continuing through it, because that moves day zero.
Why does the calculator use trading days instead of calendar days?
Because exercising happens through a broker and stock-plan administrator that are only open on trading days. A window that ends on a weekend or a market holiday is not actually usable that day, so the tool counts in NYSE/NASDAQ trading days to show the real, transactable deadline. If your plan states the window in calendar days, set the day count to match and treat the result as the last day you can practically act.
Is the deadline different for ISOs, and is this advice?
It can be. To keep Incentive Stock Option tax treatment, U.S. tax law generally requires exercise within three months of leaving (one year for disability); after that an ISO is taxed as a non-qualified option even if your plan's overall window is longer. This is general information only, not financial, tax, or legal advice — confirm any real deadline against your plan documents and a qualified advisor.