I have always done what you recommend, namely enter into Turbo Tax the information on our SSA-1099's, and let the software decide what to do with that data. But I just received a letter from the IRS on our 2021 return, contesting what TT entered for cell 6B, the taxable amount of the total benefits that appear (correctly) in cell 6A. To respond, I need to find out, how does Turbo Tax determine the taxable amount? I did check (not that I expected this to be what was done), it is not a subtraction of the other items on the 1099, the Medicare amount and the income tax withheld.)
