The box "Check if decrease is due to sale or exchange of partnership interest" will be checked if you sold or exchanged all or part of your partnership interest to a new or pre-existing partner during this tax year, regardless of whether you recognized gain or loss on the transaction(s). You may have realized a gain or loss on the transfer or disposition of your interest. See codes AB, AC, and AD on line 20 for items that have special gain or loss treatment.
