Limited Partnership tax basis

How do I determine the cost basis for shares I owned in a publicly traded limited partnership? The partnership recorded a loss which reduced my Ending Capital Account balance on the K-1 but I was not able to take the loss on my tax return due to not materially participating in the business (passive income). Do I add this loss back to the Ending Capital Balance even though the K-1 shows a different amount since they deducted the loss? No, your basis is reduced by any net loss and also by any distributions in box 19. Turbotax keeps track of that suspended loss but not your tax basis. when you finally sell that interest in a fully taxable transaction the suspended loss is allowed.  as a surprise you will receive a sales schedule that will report your cost basis but  to that must be added any income reported on the schedule as section 751 recapture or even gain subject to recapture as ordinary income  it will also be on box 20AB

I also have information in lines 1 and 2 on the K-1 Part III. I understand you enter a second K-1 in Turbo Tax. Do you enter all information from Parts I and II again or just the amount from line 2 for Part III. 

you report each line only once.  in Turbotax you need two k-1s one for line 1 and one for line 2. the issue is that certain lines may relate to neither 1 or 2 such as interest income so they can go on the first k-1. others relate only to lines 1 or 2 so that should go on the related k-1.  it's possible that some could relate to both. in that case the partnership may provide a schedule showing which item relate to which line - 1 or 2