Insurance premiums paid by the S-corp for a more-than-2% shareholder must be reported by the S-corp as wages. Then, when you the shareholder are entering the Schedule K-1, in the follow-up to entering the Schedule K-1 TurboTax will present a page with several checkboxes where you must mark the box that indicates that you personally paid health insurance premiums and the S-corp paid you wages. Because the S-corp was required to include the amount in your wages, you are considered to be the one who paid the premiums.
The selection that DawnC highlighted is never used to enter a self-employed health insurance deduction. (Perhaps it was done there in the distant past, but that selection has not been used for many years.)
