I am not asking about a conversion from 401K to Roth IRA. (That'd be Form 8606 by the way).
My employer plan allows both traditional and Roth 401(K). Really. They also allow Roth conversions from traditional 401(K) to Roth 401(K).
However, the Roth conversion needs to be reported on taxes. What form is used?
By all evidence, Form 8606 is the wrong form for conversions to Roth 401(K) since neither the form nor the instruction contains the keyword "401" anywhere in it. Am I mistaken about that?
(There was a joke in M.A.S.H. where a field platoon could get a soda fountain, they just took a different military form and crossed out "Machine gun" and wrote "Soda fountain". Is this like that, and I use 8606 anyway? Do I cross something out?). I also have IRAs and I don't want those confused.