I hear this question a lot—and it’s a smart one to ask before you exercise. Incentive Stock Options (ISOs) can be a meaningful wealth-building opportunity, but they come with a unique tax “gotcha”: exercising ISOs can increase your risk of triggering the Alternative Minimum Tax (AMT) in the year you exercise.
Why exercising ISOs can create AMT exposure
Under the regular tax system, exercising an ISO (and holding the shares) typically isn’t a taxable event at that moment. But under the AMT rules, the IRS may treat the “spread” as income:
- Spread = (Fair Market Value at exercise) – (Exercise price)
- That spread is often considered an AMT adjustment—even though you didn’t sell the shares and may not have cash on hand to cover taxes.
In plain English: you can owe tax based on an unrealized gain.
When the AMT risk tends to be higher
AMT is very fact-specific, but these factors commonly increase risk:
- A large spread between the exercise price and the current value
- Exercising and holding a lot of shares in one calendar year
- Higher household income (AMT exemptions phase out at higher income levels)
- Certain deductions that are limited under AMT rules (for example, some state and local taxes)
A simple example
Imagine your exercise price is $5 and the current value is $25. That’s a $20 spread per share. If you exercise 5,000 shares, the AMT “income” adjustment could be $100,000 ($20 × 5,000). Depending on your full tax picture, that additional amount could push you into AMT.
Common planning approaches to discuss
Because you can’t know the outcome from rules of thumb alone, many families coordinate ISO decisions with a proactive tax projection. Some approaches that may come up in planning conversations include:
- Staging exercises over multiple years to manage the spread and income impact
- Exercising earlier in the year (giving more time to evaluate whether selling later makes sense)
- Considering whether a same-year sale (a “disqualifying disposition”) better fits your cash-flow and risk tolerance
- Reviewing the potential benefit of an AMT credit in future years (not guaranteed, but often part of the longer-term analysis)
A steady next step
If you’re considering exercising ISOs, it’s worth running a year-by-year scenario: how many shares, which year, what spread, and how it interacts with the rest of your income and deductions. If you’d like, we can coordinate with your tax professional and map out a strategy that supports your bigger goals—without unwanted surprises.
The views stated in this material are not necessarily the opinion of Cetera Wealth Services, LLC and should not be construed directly or indirectly as an offer to buy or sell any securities mentioned herein. Due to volatility within the markets mentioned, opinions are subject to change without notice. Information is based on sources believed to be reliable; however, their accuracy or completeness cannot be guaranteed. Past performance does not guarantee future results.