I sold an Membership interest in an LLC in 2019. I will receive payments for the interest in 2020 and beyond. I had a negative basis in my Capital account at the time of sale. I am trying to record this sale on my 1040 as an Installment Sale but Turbo Tax will not let me file my return with a negative number on Line 8, Part 1 of Form 6252 - Cost or other basis of property sold. I am trying to recognize the recapture of my negative basis as a gain in 2019 and report the gains from payments received in future years. How can I report this sale on my return correctly if Turbo Tax will not let me use Form 6252 to do so?
