In my unprofessional opinion you need to know at least two things to get an idea of whether or not you will owe taxes when you exercise: 1) the strike price you pay to exercise your options, 2) the current fair market value (FMV) of the stock
You will only run into this AMT trap if there is a difference between 1 and 2. This could happen if you were granted options a long time ago and your company has since raised new rounds which increased the valuation. This is when the IRS eyes your exercized options as 'income' unlike the normal case with ISOs where the strike price and FMV are pretty close.
You will only run into this AMT trap if there is a difference between 1 and 2. This could happen if you were granted options a long time ago and your company has since raised new rounds which increased the valuation. This is when the IRS eyes your exercized options as 'income' unlike the normal case with ISOs where the strike price and FMV are pretty close.
EDIT: see this excellent post elsewhere in this discussion: https://news.ycombinator.com/item?id=12565340