" Would that not raise a red flag with the the IRS??"
With a zero in box 2a, the information from the Form 1099-R will not add anything to your tax return even if entered and will not affect you income as calculated by the IRS Automated Under-reporter System, so I don't see how the IRS would detect any discrepancy.
TurboTax is asking for the explanation because of the zero in box 2a which has special meaning to TurboTax. Omitting the Form 1099-R eliminates the problem.
