I got a lump sum payment in 2021 that covers the years 2021, 2020 and 2019. I entered that information into TurboTax and it calculated box 6b and entered a number based on the default method of calculating this value. However, I followed the instructions I got from the IRS website which said I could use an alternative method if that would reduce my taxes. I did that method and found that it did indeed reduce my taxes. However, I have no way to enter that data into TurboTax.
It is unclear to me why TurboTax did not use the alternate method of calculation. Please advise.
