Yes, you are correct about the S Corp not needing to keep track of the basis for the shareholders, but in this case since I am filing returns for all shareholders it is easiest solution. I hope Proseries adds a basis computation worksheet for 1040's sometime soon, because if I get a 1040 that I do not file the 1120S I will have to manually draft up a basis statement to attach. Bill, have you ever run into this issue before?
Also, I just discovered that at in February 2019 the IRS posted a clarification that basis statements are required if an S Corp shareholder reports a loss, receives a distribution, disposes of stock, or receives a loan repayment. Since most all shareholders receive distributions, this means a basis statement is almost always required.