As I said that is not "in plan". What you are referring to is an ordinary 401(k) plan direct rollover/conversion of after tax money to a "out of plan" personal Roth IRA. That is done all the time. Many 401(k) plans don't allow that before retirement age, but some do. Again that has not affect on any basis that you might have in a Traditional IRA.
An "In Plan Roth Rollover" (IRR) is reported differently on a 1099-R than is a Roth IRA Conversion is.
See IRS rules for the 1099-R reporting:
https://www.irs.gov/instructions/i1099r#idm140302484507984
**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.**
