How do you account for taxed contributions from a Company 401k rollovered to an IRA for RMD calculations.?

[dmertz]

No, Form 8606 was not required at the time of the rollover from the 401(k) to the IRA.  With regard to traditional IRAs, Form 8660 is only required for new regular nondeductible contributions (a nonzero line 1) and for distributions (lines 7 or 😎 if your traditional IRAs have basis.  The IRS expects you to remember that you rolled basis from the 401(k) to the IRA and to report it on the next Form 8606 required to be filed, even if that is many years later.

[dmertz]

It doesn't matter how the money was invested.  Your basis in traditional IRAs does not apply to any particular investment, it applies to all of your traditional IRAs in aggregate.  Assuming that you made no regular contributions to your traditional IRAs that you did not deduct, your basis in your IRAs is simply the amount of basis transferred from the 401(k).  That amount would normally have been reported in box 5 of the Form 1099-R that reported the lump-sum distribution from the 401(k), which should agree with the basis amount shown on your 401(k) statement.

[lousau]

Thank you. I will go back to the 1099R and check that out.