What Happens to My Stock Options When I Leave My Job?
Last reviewed: July 2026
When you leave a job, your stock options usually come with a deadline: you typically have 90 days from your last day to exercise any vested incentive stock options (ISOs), or you forfeit them. Unvested options are generally gone the moment you walk out. That 90-day window is the single most expensive thing nobody warns tech employees about, because exercising can cost tens of thousands in cash plus a surprise tax bill.
Key Takeaways
- You generally have 90 days after leaving to exercise vested ISOs before they lose their favorable tax status or expire entirely.
- Exercising ISOs can trigger alternative minimum tax on the paper gain, even before you sell a single share.
- The 2026 AMT exemption is $90,100 for single filers and $140,200 for married filing jointly, which affects how much AMT you owe.
- Unvested options are usually forfeited immediately on your last day, so timing your resignation matters.
- You can exercise partially instead of all-or-nothing to balance upside against cash risk.
About the Author: Jeff Judge, CFP®, AEP®, ChFC®, CLU® is Managing Partner of Chesapeake Financial Planners in Forest Hill, Maryland. He has been helping families and business owners in Harford County and the Baltimore metro area navigate equity compensation decisions since earning his CFP® certification in 2013, by using Chesapeake Financial Planners’ signature process, the R.U.D.D.E.R. method™. Jeff has watched more than one engineer leave six figures of vested equity on the table simply because nobody told them the 90-day clock started the day they gave notice.
What Is the 90-Day Rule for Stock Options?
The 90-day rule, formally called the post-termination exercise period (PTEP), gives you a limited window after leaving a company to exercise your vested stock options. For incentive stock options, the tax code requires that you exercise within 90 days of separation to keep ISO tax treatment. Exercise on day 91, and the IRS reclassifies them as non-qualified stock options (NSOs), which are taxed as ordinary income on the spread.
The rule traces back to the Internal Revenue Code Section 422, which sets the conditions an option must meet to qualify as an ISO. The 90-day clause is one of those conditions.
Here is the part that catches people off guard: this is a cash decision made at the worst possible time. You are onboarding at a new job, maybe relocating, sorting out benefits, and somewhere in that chaos you have three months to decide whether to write a five- or six-figure check for shares you cannot sell.
Some employers have extended their PTEP to seven or even ten years, which removes the trap entirely. But that is still the exception. Always ask about your post-termination exercise period before you accept an offer, not after you resign.
How Much Does It Cost to Exercise Stock Options When Leaving a Job?
Exercising stock options when leaving your job costs the strike price times the number of shares, plus any tax triggered by the exercise. The strike price is locked in, but the tax piece is where most people underestimate the bill.
Say you hold 10,000 ISOs with a $2 strike price, and your company's most recent 409A valuation puts fair market value at $25 per share.
| Cost Component | Calculation | Amount |
|---|---|---|
| Shares (strike price) | 10,000 × $2 | $20,000 |
| AMT income (the spread) | 10,000 × ($25 − $2) | $230,000 |
| Estimated AMT owed | depends on income | roughly $50,000–$60,000 |
So a "$20,000" decision can balloon into an $80,000 cash outlay once AMT enters the picture. And you are spending that money on private-company shares you cannot sell. If the company fails, you are out the entire amount.
That is the real shape of the decision. Walk away and forfeit equity that could be worth $250,000, or exercise and risk a large cash loss if the company never reaches liquidity. Neither answer is automatically right.
Why Does Exercising ISOs Trigger the Alternative Minimum Tax?
Exercising ISOs triggers the alternative minimum tax because the IRS treats the spread between your strike price and the fair market value as income for AMT purposes, even though you have not sold anything. For regular income tax, exercising an ISO is not a taxable event. For AMT, it is. That mismatch is what burns people.
Using the example above, the spread is $23 per share, or $230,000 across 10,000 options. That entire amount gets added to your AMT income calculation. The 2026 AMT exemption shields the first $90,100 for single filers or $140,200 for joint filers, but the exemption phases out at higher income levels. Above that, AMT is calculated at a 26% or 28% rate.
You can end up owing the IRS real money for shares that are worth nothing on paper because they are illiquid, and that might be worth literally zero if the company folds.
This is not hypothetical. The dot-com bust of the early 2000s bankrupted employees who exercised at high valuations, owed enormous AMT bills, then watched their shares collapse. The IRS still wanted its money. According to the IRS, AMT is a parallel tax system designed to ensure taxpayers with significant deductions or preference items still pay a minimum amount, and ISO exercises are one of the largest preference items there is.
Jeff Judge often tells clients the AMT trap is the most misunderstood line item in equity comp. People think exercising is free until the spread shows up on their tax projection. The good news is that the AMT you pay can generate a credit you recover in future years; that is a separate planning conversation worth having. How do I recover the AMT credit after exercising ISOs?
How Should You Decide Whether to Exercise?
Decide whether to exercise by running three numbers and one judgment call: the cash cost, the AMT exposure, the company's odds of reaching liquidity, and your own ability to absorb a total loss. If you cannot afford to lose every dollar you put in, that is your answer before the math even starts.
At Chesapeake Financial Planners, we work these decisions through the R.U.D.D.E.R. Method™, Chesapeake Financial Planners' six-step planning process: Review and Recognize, Uncover and Understand, Design and Develop, Discuss and Decide, Execute and Empower, and Reassess and Refine. For equity comp, the "Uncover and Understand" step is where the AMT projection lives, and it is the step people skip.
Here is the practical framework:
- Know your numbers. Strike price times shares gives your exercise cost. The spread times shares gives your AMT income. Run an actual AMT projection with a tax advisor before you commit.
- Assess the company. Is there a credible path to liquidity through an IPO, acquisition, or secondary sale? Is revenue growing? Do you still believe in the business?
- Evaluate your capacity. Can you exercise without draining your emergency fund or derailing other goals? What is your tolerance for an illiquid, concentrated bet?
- Consider exercising partially. This is rarely all-or-nothing. Exercise enough to keep meaningful upside without betting money you cannot afford to lose. If you hold both ISOs and NSOs, ISOs usually get priority for their better tax treatment.
When does exercising incentive stock options trigger the AMT?
The mistake Jeff sees most often is treating this as a yes-or-no question under time pressure. It is not. Partial exercise, combined with an honest read on the company, almost always beats a panicked all-in or a regretful walk-away.
What happens to my stock options when I leave my job?
Frequently Asked Questions
What happens to my unvested stock options when I quit?
Unvested stock options are almost always forfeited the day you leave, with no exercise window at all. Only vested options qualify for the post-termination exercise period. This is why the timing of your resignation matters: leaving a few weeks before a vesting date can cost you a meaningful chunk of equity that would otherwise have been yours to exercise.
How long do I have to exercise stock options after leaving a job?
You typically have 90 days after your last day to exercise vested incentive stock options while keeping ISO tax treatment. Some companies extend this post-termination exercise period to seven or ten years, but the 90-day standard remains common. Always confirm your specific PTEP in your option agreement, because the window varies by employer and option type.
Do I have to pay taxes when I exercise ISOs even if I do not sell?
Yes, exercising ISOs can create alternative minimum tax liability even though you have not sold the shares. The spread between your strike price and the fair market value counts as income for AMT purposes. You could owe the IRS a substantial bill on a paper gain, which is why a tax projection before exercising is essential, especially for private-company stock.
What is the difference between ISOs and NSOs when leaving a job?
ISOs and NSOs are taxed differently at exercise. ISOs can trigger AMT but avoid ordinary income tax on the spread if you meet holding requirements, while NSOs are taxed as ordinary income on the spread immediately. If your 90-day ISO window lapses, your ISOs convert to NSOs, which usually means a higher tax bill. Prioritize exercising ISOs first when you hold both.
Can I exercise only some of my stock options instead of all of them?
Yes, you can exercise a portion of your vested options rather than all of them. Partial exercise lets you keep meaningful upside while limiting the cash you put at risk on illiquid shares. Many tech employees exercise the amount that fits their budget and AMT tolerance, then forfeit or let the rest expire. This is often the most balanced choice under a tight deadline.
What to Do Before You Give Notice
The 90-day trap is avoidable if you plan before you resign, not after. Map your vested versus unvested options, get a real AMT projection, and decide what you can afford to lose before the clock starts. If you found this helpful, our equity compensation planning guide walks through these decisions in depth for tech employees. Download it at chesapeakefp.com and get ahead of the deadline instead of scrambling inside it.
What is the best financial planning strategy for a tech company employee with equity compensation?
Want to go deeper? Our Stock Option Strategy Worksheet walks through this step by step.
Disclosures
The information provided is for educational purposes only and should not be construed as investment advice. Investment strategies should be tailored to individual circumstances, risk tolerance, and goals. Past performance doesn't guarantee future results. Consult with qualified financial professionals regarding your specific situation.
Advisors associated with Chesapeake Financial Planners may be either (1) LPL Financial Registered Representatives offering securities through LPL Financial, Member FINRA and SIPC, and investment advisor representatives offering investment advice through Great Valley Advisor Group; or (2) solely investment advisor representatives offering investment advice through Great Valley Advisor Group and not affiliated with LPL Financial. Great Valley Advisor Group, and Chesapeake Financial Planners are separate entities from LPL Financial.
