The form 8606 tracks your contributions to a traditional IRA. distributions from a ROTH IRA and when funds are converted. If it is a year with none of these, the form is not used. Here is Form 8606 (PDF)   See Where do I find Form 8606?   @nlassman     @tc32 It sounds like you should have had 8606 in your returns. You should go back and create the 8606 and send it in. You can mail the 8606 separately. See Instructions for Form 8606 (PDF)  Go back to your old returns, download as if you will amend. You will not amend, just force the 8606 and print it. ... View more

PEJ, you understand the instructions and Form 8606 correctly.  Rolling your 401(k) over to your traditional IRA has decreased the proportion of your nondeductible traditional IRA contributions to the overall value of your traditional IRAs, resulting in a decrease in the nontaxable proportion of your RMD and more of your basis remaining in your traditional IRA(s) to be applied to future distributions.  This result is dictated by law. ... View more