@desperado @nexchap I'll provide what I did if helpful. With the guidance from Nexchap, using the K-1 provided from the MLP, I completed the TT K-1 interview, noting the sells (ordinary gains/AMT) as provided in the K-1 sales schedule and entered the cost basis as the inverse of the amount provided.
In my case, by broker provided a 1099-B as NOT reported to the IRS, with an incorrect cost basis. Using the TT 1099-B interview, I added the MLP sales as short-term (in my case) NOT reported to the IRS. Right or wrong, I chose to enter the sales shown in the 1099-B, and then to add an adjustment to correct the cost basis per the K-1 sales schedule noting that the cost basis is incorrect (from the list of reasons in the TT adjustment screen). The reason I chose to use the adjustment option is that TT requires that you attach a copy of the 1099-B NOT reported to the IRS to conclude the 1099-B interview, stating that the IRS needed it. I figured it may make more sense to the IRS to see that an adjustment was made compared to the 1099-B, although I'm not too sure how the adjustment entry was ultimately recorded in my final 1040.
