Alternative Minimum Tax calculation for stock option

[kaichieh7882]

If my company's 409A valuation changed after I exercised my stock option (ISO) during the tax year, should I calculate Alternative Minimum Tax based on the company stock value at the time of exercise or that at the end of the tax year?

[kaichieh7882 · Accepted solution]

Found the answer. As of today, the Fair Market Value per share of the company at the end of the year is used.