The Moment
Your company granted you incentive stock options (ISOs). The stock price has risen above your strike price, and the "spread" (current price minus strike price) represents real money — $50,000, $100,000, or more on paper.
ISOs are the most tax-complex form of equity compensation. Unlike RSUs (taxed at vesting) or NSOs (taxed at exercise), ISOs have a unique tax structure that can create a massive surprise tax bill if you do not plan carefully.
The Tax Trap: AMT
When you exercise ISOs, the spread is not taxed as ordinary income. This sounds great — but the spread is included in your Alternative Minimum Tax (AMT) calculation. If the spread is large enough, you owe AMT even though you have not received any cash.
Example: You exercise 10,000 ISOs with a $10 strike price when the stock is at $25. Spread = $15 × 10,000 = $150,000. This $150,000 is added to your AMT income. At a 28% AMT rate, you could owe $42,000 in AMT — on stock you have not sold and may not be able to sell (if the company is private).
The nightmare scenario: You exercise ISOs, owe $42,000 in AMT, and then the stock price drops. You owe tax on gains that no longer exist. This happened to thousands of people during the dot-com crash.
The Two Strategies
Strategy 1 — Exercise and sell same year (disqualifying disposition) Exercise the options and sell the shares immediately (or within the same calendar year). The spread is taxed as ordinary income — same as an NSO. You avoid AMT entirely because the shares are no longer held at year-end. You get cash in hand and can pay taxes from the proceeds.
*Best for:* Most people. Eliminates AMT risk, provides certainty, and generates cash for diversification.
Strategy 2 — Exercise and hold (qualifying disposition) Exercise the options, hold the shares for 1 year from exercise AND 2 years from grant, then sell. The spread is taxed at long-term capital gains rates (15-20%) instead of ordinary income rates (22-37%). Potential tax savings: 7-17% on the spread.
*Best for:* People with low AMT exposure, sufficient cash to pay AMT, and high confidence the stock will not decline. Requires a CPA to model the AMT impact before exercising.
The critical rule: Never exercise and hold ISOs without first having a CPA model your AMT liability. The potential tax savings of qualifying disposition are not worth the risk of owing $20,000-$100,000 in AMT on stock that may decline.
Run Your Numbers
Enter the value of your ISO spread.
$50,000 Windfall Allocator
What to explore next
- →How do I calculate my AMT exposure from ISO exercise?
- →What is the difference between ISOs and NSOs?
- →Should I exercise options before my company IPOs?
Frequently Asked Questions
What if my company is private and I cannot sell the shares?
This is the highest-risk scenario. Exercising ISOs in a private company triggers AMT on a spread you cannot monetize. Unless you have strong conviction in the company's trajectory and sufficient cash to pay AMT, wait to exercise until a liquidity event (IPO, acquisition, secondary sale). Some companies offer early exercise, but this carries its own risks.
Can I exercise a small number each year to minimize AMT?
Yes — this is the 'AMT-optimized exercise' strategy. Your CPA calculates how many options you can exercise each year without triggering AMT (or keeping AMT to a manageable amount). This spreads the tax burden over multiple years and is the most sophisticated approach.