My guess is that if you meet all the requirements, (had a refund, paid AMT, itemized deductions, etc.) then you will get some benefit from re-doing last years taxes to exclude some of your refund from this year's taxes. My even more nebulous guess is that if your last year's AMT tax amount is, say, twice the amount of your refund, then you likely can exclude all of last year's refund from this year's taxes. I did not re-calculate my 2016 taxes, but I did take advantage of the Recovery Exclusion form to figure out NOW whether my 2017 refund can be excluded from my 2018 tax return. It was a simple form to use, and in my case, the answer was that all my refund can be excluded in 2018. My AMT tax amount was about twice the amount of my refund, leading to my "nebulous guess" above.
