Again you do not change box 2a to account for prior after-tax distributions. That is asked for in the 1099-R interview. If a Traditional IRA then prior year after tax distributions were required to be reported on a 8606 form for each year that there was such a contribution. The IRS can access a $50 penalty for each year that a 8606 was require to be filed by was not. The IRS will often waive the penalty if the missed 8606 form are filed late with a explanation.
If not a IRA then the interview asks for other methods of calculating the taxable amount.
**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.**
