lump sum SSDI for "other years"

[blurghtaxesarehard]

Two Questions: In 2023 I received SSDI benefits going back to 2016.  My SSA-1099 only breaks it down by year through 2019, then says "paid in 2023 for Other Tax Years."  Since this encompasses 2016-2018, I don't know how to enter AGI because I don't have the breakdown for those years (I've tried calculating and - surprise - based on my monthly award for each of those years, it doesn't match the numbers the government calculated).  Due to my spouse's salary, we owe tax and it's just a question of how much on this  large lump sum.

1) How do I enter the "Other Tax Years" lump sum?  All with the year 2018 and my AGI in 2018?

2) for each previous year TurboTax asks me to enter the "Taxable Social Security Benefits" for that year.  I don't know the answer to this question without completing the SSA worksheets on my own.  HELP!

[AnnetteB6]

Unless you can get a breakdown of the information for the lump sum payments allocated to 2016-2018, you could use your best estimate to determine what amount to allocate to each year.  For example, if the payments are essentially equal for the years that you do have a breakdown, make the assumption that that would also be the case for 2016-2018.  Then, create a worksheet for each year.

For your second question about 'Taxable Social Security Benefits' for that year, enter the amount of taxable benefits that were reported on your tax return for that year, not the amount that is determined to be taxable after filling in the worksheets.  For example, if no Social Security benefits were received at all for a particular year, then nothing would have been reported and nothing would have been taxable.