It would appear that the 1099-R is not correct. If box 2b (not determined) is checked then box 2a must be BLANK, not zero. Check again - an empty box 2a is NOT the same as zero - it it the opposite in most cases and means the that box 1 is probably the taxable amount unless you had after-tax basis in the account.
Code 3 means disability and the taxable amount (probably box 1) should be included as wages if you are under retirement age or taxed as a pension of over retirement age.
It sounds like you either entered a zero for box 2a when it was blank or the 1099-R is incorrect.
You should check with the issuer of the 1099-R.
**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.**
