@RC519
Did you pay according to the Form 8606 calculation.??
If so, but you did not file Form 8606, (not clear how this could happen) you should do so by attaching it to Form1040-X with an explanation.
That's all there is to it.
If the form calculation changes your tax due, then you have to file 8606 and any other forms and schedules that changed due to your amendment.
