Generally, if you have received a lump-sum payment from Social Security there will be an amount in box 3 of your SSA-1099 Form. The years for which the lump-sum payment is for should also be reported on your SSA-1099 Form, in the box that states "Description of Amount in Box 3".
The amount in box 5 shows your net benefits for 2024 (box 3 minus box 4). Box 5 is used to figure out whether any of your benefits are taxable. You will only have to enter Box 5 & 6 in TurboTax along with Medicare premiums reported in the description box for Box 3.
To enter your Form SSA-1099 in TurboTax you can do the following:
Your TurboTax screens will look something like this:
Check box "Description of Amount in Box 3" for the years:
Click here for "Where do I enter an SSA-1099, SSA-1099-SM, or SSA-1099-R-OP1?"