I actually called TurboTax with the same question today. The person I asked, couldn’t help me and was guessing the entire time. The amount I did last year in that block was not a figure that was readily apparent on any of the completed forms, but the person who helped me last year said it was the number he had on his computer (he could see the data). I’m with everyone else, Turbo Tax should do the supplemental forms when they have all data necessary to complete them!