Did you answer Yes to indicate that this was an In-plan Roth Rollover when asked if the money was rolled over to a Roth 401(k) or Roth 403(b)? Failing to answer Yes to this question will result in TurboTax treating this distribution as nontaxable. If you did answer Yes, you should see the taxable amount (then entire amount) of this IRR appearing on Form 1040 line 5b.
