If after you do the Roth conversion, if there is any value in any Traditional, SEP or SIMPLE IRA account anywhere, then as said above, the non-deductible basis must be prorated between the conversion amount and the year end total value so only a part of the conversion will be non-taxable.
Only if no such account exists at years end will all of the non-deductible basis be applied to offset the taxable amount. If the amount converted exceeds the amount of non-deductible (after-tax basis) the excess (gains and growth) is taxable income.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
