When to Exercise Stock Options at a Startup: A Decision Framework

Knowing when to exercise your stock options is one of the most consequential financial decisions you'll make as a startup employee. Exercise too early and you tie up cash in a company that might fail. Wait too long and you face a crushing tax bill — or lose the options entirely when you leave.

In 60 seconds:

• NSOs generally trigger ordinary income at exercise; ISOs can qualify for capital gains treatment but can also trigger AMT.
• Exercising earlier locks in a lower strike and starts the long-term clock, but increases cash and AMT risk if the company doesn’t exit well.
• Waiting reduces cash risk, but can increase the tax bill and risk forfeiture if you leave before you can exercise.
• Washington overlay: capital gains tax already exists (7% above $250,000); the 2028 income tax adds another layer, so timing matters.

This guide gives you a framework for making the decision. It covers the five main exercise strategies, the tax implications of each, how Washington state's new taxes change the calculus, and what to do when you're running out of time.

The Five Exercise Strategies

There's no universal right answer. The best strategy depends on your company's stage, your cash position, your tax situation, and your confidence in the outcome. Here are the five approaches, ranked roughly from earliest to latest.

1. Early Exercise at Grant (Before Vesting)

Some companies allow you to exercise options immediately — before they vest. You buy the shares right away at the strike price (which equals the 409A fair market value at the time of grant, meaning the spread is zero or close to it). The shares remain subject to the company's repurchase right until they vest.

You must file an 83(b) election with the IRS within 30 days of exercise. This tells the IRS you want to be taxed on the value at exercise — which is essentially nothing if you exercise at grant.

Why this works:

• The spread is zero, so there's no ordinary income and no AMT adjustment.
• All future appreciation is capital gains, taxed at lower rates.
• The long-term capital gains holding period starts immediately.
• If the stock qualifies as QSBS, the five-year holding period starts at grant.

The risks:

• You spend real money on shares that might become worthless.
• If you leave before vesting, the company repurchases your unvested shares — usually at the price you paid, but you don't get a tax refund on the 83(b) election.
• Not all companies allow early exercise. Ask.

Best for: Employees who join early (when the strike price is low), who have the cash, and who have high conviction in the company.

2. Exercise Shortly After Vesting Begins

Once your shares start vesting (typically after the one-year cliff on a standard vesting schedule), you exercise each batch as it vests. The spread is still relatively small because the company is still early-stage and 409A values haven't climbed much.

Tax implications:

• For ISOs: the spread at exercise is an AMT adjustment. If the spread is small, you may stay under the AMT exemption and owe nothing additional.
• For NSOs: the spread is ordinary income, reported on your W-2.

Best for: Employees at Series A/B companies where the 409A is still in single digits and the exercise cost is manageable.

3. Exercise Strategically Over Multiple Years

Rather than exercising everything at once, you spread exercises across two or more tax years. This lets you manage the AMT impact (for ISOs) or the ordinary income hit (for NSOs) by staying below key thresholds each year.

Key thresholds to manage around:

• AMT exemption phase-out: $500,000 AMTI for single filers in 2026. Stay below this to keep your full exemption.
• Washington income tax threshold: $1,000,000 household income, starting 2028. Keep annual income below this to avoid the 9.9% state tax.
• Federal bracket management: The jump from the 32% to 35% bracket (at ~$231K for single filers) and 35% to 37% (at ~$578K) are worth planning around for NSO exercises.

Best for: Employees with large grants, especially those who can forecast their income across multiple years.

4. Exercise When Liquidity Is Imminent

Wait until the company announces an IPO filing, a direct listing, or an acquisition. Then exercise shortly before the event, knowing you'll be able to sell shares to cover the tax bill.

The appeal: You never risk cash on a company that doesn't make it. You only exercise when there's a clear path to liquidity.

The problems:

• The spread at exercise will be large — potentially hundreds of thousands or millions of dollars.
• For ISOs, this creates a massive AMT bill. For NSOs, a massive ordinary income hit.
• After an IPO filing, you typically can't sell for six months (lock-up period) to a year. You owe the tax now but can't sell to cover it.
• In Washington starting in 2028, if the exercise pushes your income over $1 million, you'll owe 9.9% to the state on the excess.
• You've missed the window for QSBS qualification if you haven't held the shares for five years.

Best for: Risk-averse employees who want certainty, and who have the cash reserves to handle the tax bill during the lock-up period.

5. Never Exercise (Let Options Expire)

This isn't a strategy anyone plans — but it's what happens to roughly 50% of startup options. The company never reaches a liquidity event, or you leave before one and can't afford to exercise during the post-termination exercise period.

This is the outcome you're trying to avoid. The rest of this guide is about making sure you don't end up here.

Exercise Methods: How You Actually Pay

Once you've decided when to exercise, you need to decide how to fund it.

Cash exercise. You write a check for the full exercise price. The simplest method, and the only one available at most private companies. If you're exercising 10,000 shares at $2, you need $10,000.

Cashless exercise (same-day sale). You exercise and immediately sell enough shares to cover the exercise price and taxes. This only works at public companies or during company-sponsored secondary sales. No out-of-pocket cost, but you give up some of your shares.

Net exercise. The company withholds a portion of your shares to cover the exercise price. You receive fewer shares, but you don't pay cash. This is uncommon at startups — most private companies don't offer it.

Borrowing. Some fintech lenders (ESO Fund, Secfi, and others) will advance the cash to exercise your options in exchange for a share of future proceeds. This is expensive — effectively a high-interest loan with equity kicker — but it exists for employees who can't afford to exercise otherwise.

The Tax Decision Tree

The tax treatment of your exercise depends on two things: what type of options you hold and when you sell the shares.

ISOs — exercise and hold (qualifying disposition):

• No regular income tax at exercise.
• The spread is an AMT adjustment — you may owe federal AMT.
• At sale (if you've held 2+ years from grant, 1+ year from exercise): gain is long-term capital gains.
• In Washington: gain above $250K subject to capital gains tax (7%–9.9%).

ISOs — exercise and sell same year (disqualifying disposition):

• Spread is ordinary income on your W-2.
• No AMT adjustment.
• In Washington starting 2028: if total income exceeds $1M, 9.9% state tax on the excess.

NSOs — exercise:

• Spread is always ordinary income at exercise, regardless of when you sell.
• In Washington starting 2028: same $1M threshold applies.
• Post-exercise appreciation is capital gains when you sell.

The Washington planning window: Between now and December 31, 2027, there is no Washington state income tax. This means:

• ISO disqualifying dispositions generate no state tax.
• NSO exercises generate no state tax.
• Early exercise + 83(b) elections generate no state tax.

Starting January 1, 2028, any exercise event that creates ordinary income above $1 million will cost an extra 9.9% at the state level. This is a meaningful incentive to accelerate exercises into 2026–2027 if you can.

When You're Leaving: The Post-Termination Exercise Period

This is where most options die. You leave the company — voluntarily or not — and suddenly have a countdown clock.

The standard window: 90 days. Most startup equity plans give you 90 days after your last day of employment to exercise your vested options. After that, they expire and return to the company's option pool. For ISOs specifically, the tax code requires exercise within 90 days to maintain ISO treatment. After 90 days, the options automatically convert to NSOs (losing the favorable capital gains treatment).

Extended windows. Some companies now offer 5-, 7-, or 10-year post-termination exercise periods. This is a significant benefit if you can negotiate it — either at hire or at departure. About 10–20% of companies now offer extended PTEPs.

What to do if you're facing the 90-day clock:

1. Calculate the exercise cost. Strike price × vested shares. Can you afford it?
2. Calculate the tax cost. For ISOs, estimate the AMT. For NSOs, estimate the ordinary income tax on the spread.
3. Assess the company's prospects. Is a liquidity event likely in the next 2–3 years? If not, the expected value of exercising may not justify the cash outlay.
4. Ask for an extension. Companies can extend the PTEP — it requires a board resolution and plan amendment, but it's not uncommon, especially for long-tenured employees or executives.
5. Consider a partial exercise. If you can't afford all of it, exercise what you can — prioritize the lowest-strike-price grants and the grants closest to QSBS qualification.

The QSBS Factor

If your company is a C corporation with gross assets under $50 million, your exercised shares may qualify as qualified small business stock under Section 1202. The QSBS exclusion can eliminate up to $10 million in federal capital gains tax — and under current law, it also eliminates Washington's capital gains tax on the excluded gain.

But QSBS requires a five-year holding period starting at exercise (or at grant, if you early-exercise with an 83(b) election). Every year you delay exercising is a year you push back your eligibility for this exclusion.

For employees at QSBS-eligible companies, this is often the strongest argument for exercising early: the five-year clock won't start until you do.

A Decision Checklist

Here's how to think through the exercise decision:

Step 1: Know what you have. What type of options (ISO vs. NSO)? How many are vested? What's the current 409A value? When do they expire?

Step 2: Calculate the cost. Exercise price + estimated tax liability = total cash needed. For ISOs, run the AMT calculation. For NSOs, multiply the spread by your marginal tax rate.

Step 3: Assess the company. What's the realistic probability and timeline for a liquidity event? A company about to go public is a very different situation from a Series A startup with a long road ahead.

Step 4: Check QSBS eligibility. If the company qualifies, factor the five-year holding period into your timeline. Exercising now may save millions in taxes at exit.

Step 5: Factor in Washington taxes. If you're a Washington resident, model the exercise with and without the 2028 income tax. A large exercise before 2028 may save 9.9% on every dollar of ordinary income above $1 million.

Step 6: Plan for the worst case. What happens if the company fails? Can you afford to lose the exercise price? If the answer is no, exercise less or wait for more certainty.

Key Takeaways

The biggest mistake startup employees make with stock options is not making a decision at all — letting the options sit until they expire or until a forced timeline (like a 90-day PTEP) creates a bad decision under pressure.

The second biggest mistake is exercising everything at once without understanding the tax consequences — especially the AMT for ISO holders.

The right approach is to start planning early, model the tax outcomes, and make a deliberate choice. For Washington residents, the 2026–2027 window before the income tax arrives adds urgency to that decision.

Joe Wallin is a startup attorney at Carney Badley Spellman in Seattle. He advises founders, investors, and employees on equity compensation, QSBS, and Washington state tax planning. For more on equity compensation, visit the equity compensation resource page.