There is no such thing as a "in plan" conversion to a Roth IRA. A IRA is an individual retirement plan that you hold in a bank. An "in plan" Roth is still a 401(k) plan called a Designated Roth or a 401(k) Roth and is NOT an IRA and is administrated by the 401(k) administrator because it is part of the 401(k) plan - which is why it is called "in plan". Nothing is prorated at all.
**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.**
