Under these circumstances, gloriahh5200's reply is incorrect. Because the tax code prohibits your basis in nondeductible traditional IRA contributions from being rolled over to a qualified retirement plan like a 401(k), the tax code specifies that such a rollover consists only of the pre-tax money in your IRAs. (Rolling over to the qualified retirement plan more than your pre-tax IRA money result in an impermissible rollover of some amount of basis in nondeductible traditional IRA contributions, potentially subjecting the qualified retirement plan to disqualification if not corrected.) By rolling over the pre-tax money to the qualified retirement plan, the basis in nondeductible traditional IRAs is left to be converted to Roth unencumbered.
