I went in to look at my 2018 form 1040 that I had filed and had been accepted by IRS. After I updated the 2018 turbo tax, I noticed that Turbo Tax had changed my original tax file. When I pulled it up the amount due for taxes was reduced by $1397 due to changes on schedule D Tax Worksheet. Did the rules change for Schedule D? Do I need to file an amended return to get this money back? If so how do I amend it when Turbo Tax has already changed my original tax return?