assuming this was a PTP (publicly traded partnership) or MLP (master limited partnership also traded on a public stock exchange).
with the final k-1 you should have received a supplemental schedule to report the sale
enter the K-1 info
check the box PTP
check the box final k-1
check the box partner sold or otherwise disposed of the entire interest in 2020 (you sold it thru your broker)
quickzoom to enter disposition info (this is info other than reported on 1099-B)
in part II check 1a and 1a(1)
on line 2 enter sale date
on line 3 enter var (various should appear)
on line 4 indicate purchase from the drop down menu
on line 5 enter only the amount from the sales schedule that is listed as ordinary income ( to be reported on 4797 line 10)
on line 7 enter 0
on line 9 enter the same amount as on line 5
now you need to correct the 1099-B reporting. it should show the cost basis was not reported to the IRS (that's proper because the broker doesn't have a clue as to what your correct tax basis is)
your correct tax basis is either
what the sales schedule shows as cost basis + the gain subject to recapture as ordinary income
or
what the sale schedule shows as purchase price +/- cumulative adjustments to basis + the gain subject to recapture as ordinary income
not sure your version of Turbotax can handle a K-1 or if it does you have to do the above in step-by-step mode.
