How to avoid AMT when exercising ISOs
You cannot legislate the AMT away, but you can control how much spread you recognise in a given year.
Exercise early
The smaller the gap between strike and fair market value, the smaller the adjustment. Exercising soon after a 409A refresh is usually cheapest.
Exercise up to the crossover
Calculate the number of shares you can exercise before your tentative minimum tax overtakes your regular tax, and stop there. Repeat annually.
Split across calendar years
Exercise in December and January to use two years of headroom in a matter of weeks.
Disqualify deliberately
A same-year cashless exercise and sale removes the AMT adjustment entirely and taxes the spread as ordinary income. Sometimes that is the cheaper certainty.
This article is educational and not tax, legal, or financial advice. Talk to a CPA or tax advisor about your specific situation.