I can exercise ISO stock options. I want to understand if doing so will subject me to the AMT. Can't find a form 6241 from last year. Can turbotax help me calculate this?

[TomYoung]

"I can exercise ISO stock options. I want to understand if doing so will subject me to the AMT."

Well, the simple "exercise" of an ISO doesn't subject you to anything.  It's the exercise of the ISO coupled with not selling the stock before the end of the year that might, or might not, get you into AMT territory.  If you think the stock price will hold up between the date of exercise and the end of the year then you might want to wait until mid-December, when you have a good handle on all your income and deductions and when tax calculators that incorporate the 2018 tax law changes will be available, to decide to sell or not.

The 2018 tax law makes it more unlikely that you would be subject to AMT as it dramatically increases the exemption amounts offset, somewhat, by the fact that AMT tax rates were not lowered while "regular tax" rates were.  Other risk factors for falling into the AMT have also been adjusted but the net of all this - most likely - is that fewer taxpayers will be subject to the AMT under 2018 law then under the old law.

Tom Young

[midolocam]

The AMT limits your tax deductions as your income increases. You can review the instructions for IRS Form 6251. If you have TurboTax software on your PC (not online) you can estimate your tax liability based on income changes in the release for current tax year. Save a copy of your tax return for the current tax year. Then copy and save the file [Save As] with a new file name such as TY2017 Estimate. After that you can add the ISO stock transaction to the income section of your "Estimate" file. Search for AMT in the TurboTax application, and run the AMT test. Changes to your income and tax liability will appear on the top of the screen. Keep in mind that changes in the tax laws may affect your results. If you do not have the software locally, you can use the IRS AMT Assistant here: https://www.irs.gov/businesses/small-businesses-self-employed/alternative-minimum-tax-assistant-for-...
The AMT Assistant is being retired after the 2017 Tax Year.

[Jared Wenger]

Why doesn't the online version work to estimate this?  Can I just make an estimated 2019 one from my paystubs and then see if adding the ISO exercise pushes me into AMT or not?

[NCperson]

1) buy the downloadable version for $70- if you are worried about paying AMT, then spending $70 shouldn't be a big concern to discover the right answer. 

2) given how the tax laws were changed in 2018, it's unlikely you would be required to pay AMT, but again for $70 you can figure it out!