<prompt> Human: Left my old job and rolled over my 401k into an IRA. Over the next two years, not understanding the difference between traditional and Roth, I maxed it out with 5500 each year in post-tax income.I now have a separate Roth IRA that Im contributing post-tax dollars to moving forward. Though, Im wondering if theres anything I can do about that 11,000 post-tax I contributed to my traditional IRA to not pay taxes on it a second time? Somehow transfer it to my Roth IRA?Really no idea here, sorry if its a dumb question.  <response>: Yes, there is something you can do so that you will not pay taxes on it a second time.Fill out Form 8606 for the two years that you made contributions to the traditional IRA that you did not could not deduct. This will keep track of the amount of basis i.e. nondeducted contributions in the traditional IRA. The line 2 of the second form 8606 will pick up line 14 of first form 8606. In this way you keep a running tally of the basis.Later, when you take distributions from the traditional IRA, a different portion of Form 8606 is used to determine how much is taxable. The fraction basistotal balance is used to determine the non-taxable part of each distribution you take. So each distribution is partly non-taxable and partly taxable. And eventually you will have taken out all of the traditional IRA but paid taxes on the growth while not getting double taxed on the amount you did not deduct because you paid taxes on it already.Note: As soon as youve filed the late Forms 8606, you would if you want be able to convert any amount of your traditional IRA to Roth IRA, if thats something you want to do. If you have a little bit of growth there, say 500, if you convert all 11,500 from trad IRA to Roth IRA, youd find that 1100011500 11500 is nontaxable, and the rest 500 is taxable income. This is sometimes called backdoor Roth -- its a strategy used by people who are unable to contribute directly to Roth accounts because their income is too high. You can do it even if your income is not too high, though, if you want to empty your trad IRA and have future growth be in the Roth, where it will be untaxed. 