I want to exercise ISO shares, pay AMT and hold long term. Will TurboTax keep record of the 2 basis under ordinary tax and AMT tax calculation when I sell in the future?

[jk101]

My understanding is that when ISO shares are exercised and hold for more than a year, their basis for AMT purpose is FMV at exercise time, and their basis for ordinary income tax purpose is still the strike price.

[TomYoung · Accepted solution]

"Will TurboTax keep record of the 2 basis under ordinary tax and AMT tax calculation when I sell in the future?"

TurboTax can properly handle this situation, but only if when you sell the stock you go into the ISO step by step interview.  There you'll enter the Form 3921 information and TurboTax will use the exercise price for regular income tax and create a reversing entry over in Form 6251 for the "spread" between exercise price and FMV.

If you simply use the regular 1099-B interview for the stock sale and input that you're selling "Company X" stock, TurboTax isn't going to ask you "are these the share you acquired via an ISO back in 2020?"

Simply exercising and holding doesn't mean you're automatically going to pay AMT.  You might, or you might not.