After-Tax contributions to 401k after rolling into TIRA

Hi all,
I retired 5 years ago but only this year started rolling funds out of my Traditional IRA into a Roth. Suddenly I’m slamming right into the tax consequences and don’t feel at all prepared. I tried to search the forum to see if this question had already been answered but came up empty, sorry.

Over the years of my employment I’ve contributed to a couple of 401(k)’s, a 403(b), a SIMPL, Roth, and traditional IRA’s. I’ve always gotten the full employer match, sometimes made after-tax contributions, and in the last decade of my career I was maxing the before-tax limit each year.

For simplicity’s sake (or so I thought), as I left employers I rolled my plans over into a single TIRA. However, now I’m worried that I screwed up by not keeping my own spreadsheets of the various buckets of contributions. In my current statements I can’t find where my accounts are categorized in this way. I do have some or the old records, but I think at some point I figured “Heck, I’ll never need statements from my employer of 30 years ago.” Sooo…I think I may have lost the benefit of those after-tax monies.

Thanks for whatever advice – or commiseration – anyone can offer!

I don’t think an 8606 is required when you roll over your after-tax balance from a 401(k) to a traditional IRA. It will be required when you do Roth conversions.

Look at your 1099-R form that your 401(k) provider should have sent you for the year you rolled your money over to your IRA. Box 5 should contain your after-tax basis. This basis will carry forward to your IRA. You’ll need this for the 8606 when you do a Roth conversion so that the conversion can be properly prorated between pre-tax and after-tax amounts.

I was lucky. When I rolled my 401K into a tIRA, the representative that was assisting in the transaction mentioned to me that I had some after tax money in the 401K and suggested rolling it into my Roth. I am grateful that she spoke up. I would have missed that opportunity without her help.