Zero (0) is not a valid entry in box 9a. If the issuer of the 1099-R put zero in that box, they should not have. The box must be left blank with nothing in it at all. (9a is only used when the distribution is split between two or more people - very uncommon).
**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.**
