This is a pretty esoteric question but worth a shot. I have a rental property. In 2015 I had an unallowed loss. In 2016 I exercised incentive stock options which resulted a higher alternative minimum tax (AMT) income, thus requiring me to do a separate Form 8582 (Passive Activity Loss Limitations) for AMT. The difference between Form 8582 under AMT versus the regular tax system is reported on line 19 of Form 6251 (Alternative Minimum Tax). The 2016 regular tax version of Form 8582 carried over my unallowed loss from 2015. The 2016 AMT version of Form 8582 did not. Is this correct or an error by TurboTax because it didn't find a 2015 AMT version of Form 8582?
I looked closer and it turns out TurboTax did in fact do an AMT version of Form 8582 for me in 2015 (for records only, not for filing). That form shows that for AMT purposes (even though I didn't pay AMT in 2015) I was able to use the full amount of my rental loss because my AMT MAGI was lower than my normal tax MAGI by the amount of my state tax refund. So my new question is how the AMT MAGI is calculated, which I've asked here.