I need to do amended returns for 2014 and 2015. (I took an extension in both years, so 2014 is sill possible). II need to enter in tax loss carry backs for 1256 contracts

I'm guessing that you might have come in through the "Stocks, Mutual Funds, Bonds, Other" interview and if that's the case then you are in the wrong interview.  You need to use the "Contracts and Straddles" interview.  That's where you'll get asked about loss carry backs, after you click "Done" on the "Section 1256 Contracts Summary" page.

Tom Young

This answer was close, but not quite right. In my 2014 return, I went to to the Section 1256 Contracts, added a "new account". I added a new account with "IB loss from future", and then clicked, "loss from future year" in the next dialog. In my 2015 return, that is where I enter in the loss carry back for the year 2014 return.

Thanks for this info.  I was struggling with TT as to how to amend the Section 1256 contract form until I came across your post.   Thanks again....I smell refund!:-)