When Amending the return to correct the cost basis of the structure in the first year it was placed in service, one can easily get confused because of the way the program figures you're cost basis on the structure. (which is in line with the way the IRS wants it figured).
Simply increase the amount in the COST box by the appropriate amount, and do not change the amount in the COST OF LAND box. The program will "do the math" to get the cost of the structure.
Note that if you've already started or filed the 2020 tax return, then you'll have to amend it to manually correct the cost basis and the prior year's depreciation manually.
Otherwise, if you start your 2020 return after amending the prior year return, ensure that you import from the amended return, and not from the original return. Otherwise, cost basis and depreciation will be wrong.
