I have the same issue, wonder if you have figured out how to do it. My sale of ISO stocks held more than one year should lead to about -$40k AMT income adjustment. Changing cost basis of the sale only messes up with the long-term capital gain tax (schedule D), it does nothing to my AMT income. Tried to adjust AMT income under AMT review, but somehow my "Disposition of Property" was limited to about $16k, far less than the $40k adjustment I entered. Very frustrated. Any help will be appreciated. Thanks.
