I have got two homes bought in 2015 and 2016 for personal use, these are not rental properties. I bought another home and sold one of the first two in 2020 giving me three 1098 forms. As these homes were bought in different "eras" (different deduction limits apply) the Deductible Home Mortgage Interest Worksheet is supposed to merge them but it does it in the "strange" way. It calculates some kind of factor on line 15 by dividing the mortgage balance from 1987 to 2017 era with the balance from all mortgages combined. Then it multiplies the total interest from all mortgages combined with that factor. This effectively means the bigger my 2020 mortgage is, the lower my mortgage interest deduction is which is totally counter-intuitive. Am I entering my 1098 forms incorrectly, is there a bug in Turbo Tax or, if none of the previous two is correct, can I just drop the 2020 mortgage from the tax return?
