I have a traditional IRA that has a non-deductible basis amount. In 2018, I rolled my 401K and my defined contribution pension into the IRA. Does that impact the basis?

[73Bruin]

My assumption is that the basis remains the same but that it becomes a much smaller percentage when I take a distribution which I did in 2018.  This makes me wonder if I should have considered the 401k and pension when I converted amounts from the traditional IRA to my Roth IRA in 2016 and 2017.

[Hal_Al · Accepted solution]

You assumption is correct, the basis remains the same but becomes a  smaller percentage when you take a distribution. This, of course, assumes your  401K and  defined contribution pension had no after tax basis, that was also rolled over.

But, you did not need to consider the 401K and  pension, when you did  conversions in 2016 and 2017, because that money was not in an IRA, at that time. IRAs, pensions and 401ks  are taxed separately. You may have heard that you must aggregate all Traditional IRAs (TIRA), including rollovers, when you do a conversion. That does not mean all tax advantaged retirement accounts. It only means TIRAs.