An accountant filed my 2018 tax return. He filed F4797 and AMT F4797. Somehow, in the F4797, the cost of the rental house sold was real cost I paid but the AMT cost was much smaller. I could not find any cases which make me use a smaller AMT costs. I read the instructions of F4797 and F6251 but I cannot find when something like this happens. I cannot contact easily the accountant because his office is closed due to coronavirus. Thanks
