Leaving Your Employer With Equity on the Table

If you're resigning in the next few weeks, the decisions that matter most aren't about your new job — they're about closing out the equity and retirement pieces of the old one correctly, several of which run on deadlines that don't pause for a transition. Unvested grants, options with a ticking exercise clock, an old 401(k) with its own rules about staying or moving, and a deferred-comp election that isn't yours to change anymore all need a specific action, in roughly the right order, in the weeks on either side of your last day. This article walks through what happens to each one automatically, and what you still control.

What happens to my unvested equity when I resign?

Unvested RSUs and unvested stock options are, by default, forfeited the moment your employment ends — you don't get partial credit for the portion of the vesting period you've already worked, and there is no general right to a pro-rated payout. Whether your situation is actually that simple depends entirely on your specific grant agreement and your company's equity plan document, not on any external rule: some plans include acceleration provisions that vest some or all of an award early on a qualifying termination, a sale of the company, or retirement-eligibility if you've hit a minimum age and years-of-service combination, and some negotiated exit packages add acceleration that isn't in the original grant at all. If you're on any kind of garden leave or extended notice period before your official last day, check whether your plan treats you as still employed — and therefore still vesting — throughout that period, or whether vesting stops on the day you stop working even though you're still being paid. The practical trap is a vest date that lands a few days or weeks after your planned last day: absent an acceleration or retirement provision that covers you, that tranche is normally lost entirely, not prorated, which means the date on the calendar can be worth negotiating or timing around before you resign, not just noting afterward. Read the actual plan document and your grant agreement before assuming either the best or the worst case.

How long do I have to exercise my vested options?

Once your employment ends, any options you've already vested don't disappear immediately, but they don't stay exercisable forever either: your plan document and grant agreement set a post-termination exercise window — commonly counted in weeks or a few months from your last day — after which an unexercised vested option is forfeited entirely. That window is a plan design choice, not a tax rule, and it varies from company to company and sometimes from grant to grant, so the only number that matters for your own options is whatever your specific paperwork says, not a rule of thumb. For an incentive stock option specifically, there's a second, separate clock layered on top of whatever your plan allows: to keep its favorable ISO tax treatment, the option generally has to be exercised within three months after your employment ends, regardless of how much longer your plan's own window might run. Exercise an ISO after that three-month period and the option doesn't just lose a tax break at the margin — it's taxed going forward as if it had been a non-qualified option all along, meaning the spread at exercise becomes ordinary compensation income rather than qualifying for the treatment described in our article on how ISOs and NSOs are taxed. Because the plan's window and the ISO's statutory window can be different lengths, check both explicitly rather than assuming the longer one controls — the shorter of the two is the one that actually limits you.

What should I do with my old 401(k)?

An old 401(k) gives you three basic options: leave it if your balance clears the plan's minimum, roll it into your new employer's plan if that plan accepts rollovers, or roll it into an IRA. A direct rollover — where the old plan sends the money straight to the new account without ever cutting you a check — avoids the two problems built into an indirect rollover: the plan must withhold a mandatory 20% of the distribution for federal tax even though you intend to roll over the whole amount, and you then have only 60 days to deposit the full original balance, including the withheld 20% you'd have to make up out of pocket, into a new account before the shortfall counts as a taxable distribution. One age-based rule matters if you might need the money before typical retirement age: a distribution from the 401(k) of the employer you just separated from is exempt from the additional early-distribution tax if you separate from service in or after the year you turn age 55 — an exception tied specifically to that employer's plan, which does not carry over once the balance is rolled into an IRA. If the plan also holds employer stock and you take your whole balance out as a lump sum, one more decision is worth making before rolling anything over: net unrealized appreciation lets you take that stock as a direct distribution instead, pay ordinary income tax only on what the plan originally paid for it, and get long-term capital-gains treatment on the rest when you sell — a benefit a rollover gives up entirely.

What happens to my ESPP and my last vest?

If you're mid-offering-period in your ESPP when you leave, your participation typically ends on your termination date: the plan stops taking payroll deductions, and whatever you've contributed toward the current purchase that hasn't yet been used to buy shares is generally returned to you rather than used for a prorated purchase — check your specific plan document, since the exact mechanics of an early exit are a plan design choice rather than a tax rule. Separately, if an RSU tranche is scheduled to vest on or before your actual last day, that vest still runs through payroll like any other: shares are delivered, withholding is taken, and it's reported as income the same way an in-service vest would be, with your last day as the operative cutoff rather than your last paycheck date. For ESPP shares you already own from earlier purchases, leaving the company doesn't reset or accelerate anything about their tax treatment: the qualifying-versus-disqualifying disposition clocks that determine how a later sale is taxed keep running from the same offering and purchase dates they always did, regardless of your employment status — see our article on ESPP qualifying and disqualifying dispositions for how those two clocks work. The one thing that does change is who you're calling with questions about a specific transaction: once you've left, your former employer's stock plan administrator is often still the right contact for a mechanical ESPP or vesting question, separate from anything involving your 401(k) or deferred comp.

What about deferred comp and my final paycheck?

Nonqualified deferred compensation doesn't pay out just because you've asked for it or even necessarily the moment you separate — it pays out according to the distribution schedule and triggering event you elected, in advance, when you originally deferred that compensation, whether that's a fixed future date, a set number of years after separation, or something else your plan allowed you to choose. Section 409A is the reason neither you nor your employer can informally agree to move that timeline up just because you're leaving: it treats deferred compensation as if you'd received it immediately, and taxes it that way, the moment you or your employer have the ability to accelerate or change when or how it's paid outside of a narrow set of exceptions the regulations define. Practically, that means the payment date on your deferred-comp election paperwork is the date that controls, not your last day of work, and it's worth confirming what you actually elected years ago rather than assuming separation itself triggers payment. Your final paycheck is a separate, simpler matter: any accrued and unused PTO your state requires (or your employer chooses) to pay out, along with any final bonus, is supplemental wages for withholding purposes — taxed the same flat-rate way a vest or bonus is, not through your regular W-4 calculation — so don't be surprised if the withholding on that last check looks different from a typical paycheck.

Key numbers (2026)

• ISO post-termination exercise window — to keep ISO tax treatment, you generally must exercise within three months after your employment ends; exercising later converts the option to NSO tax treatment (IRC §422(a)(2)).
• Indirect-rollover deadline and withholding — an indirect rollover distribution is subject to mandatory 20% federal withholding, and you have 60 days from receipt to deposit the full original balance into a new retirement account (IRS Pub 575).
• Separation-from-service exception to the early-distribution tax — a distribution from the plan of the employer you just separated from avoids the additional 10% early-distribution tax if you separate from service in or after the year you turn age 55 (IRS Pub 575).
• 2026 elective deferral limit — $24,500 across every 401(k) or 403(b) plan you contribute to in the calendar year, even across two different employers (IRC §402(g)(1); IRS Notice 2025-67).
• §409A election lock-in — once you've elected the time and form of a deferred-comp payout, neither you nor your employer can accelerate or change it at separation outside a narrow set of regulatory exceptions (Treas. Reg. §1.409A-3).

Current as of 2026-09

Sources

• IRS Publication 575, Pension and Annuity Income — https://www.irs.gov/publications/p575
• IRS Publication 525, Taxable and Nontaxable Income — https://www.irs.gov/publications/p525
• Internal Revenue Code §422 — https://www.law.cornell.edu/uscode/text/26/422
• Treasury Regulation §1.409A-3 — https://www.law.cornell.edu/cfr/text/26/1.409A-3
• IRS Newsroom, "401(k) limit increases to $24,500 for 2026, IRA limit increases to $7,500" — https://www.irs.gov/newsroom/401k-limit-increases-to-24500-for-2026-ira-limit-increases-to-7500
• IRS Notice 2025-67 — https://www.irs.gov/pub/irs-drop/n-25-67.pdf

Sample content for demonstration purposes — not financial advice.