Importing has nothing to do with it. All importing does is save you the typing to fill in the 1099-R from boxes in the TurboTax interview. You still must go through the rest of the interview to determine the taxable amount. There are many reasons that the box 2a amount on the 1099-R is not the actual taxable amount that the interview follow-up questions determine.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
