I am a German citizen that started working as a postdoctoral researcher at a University in the U.S., being on a J1 visa.
Part of my benefits package includes an employer match that I can make use of from my second year onwards with the University.
I therefore plan to save some money for retirement by contributing to a Roth IRA on a post-tax basis for the first year, and then switch to the universities 403b plan when I become eligible for the employer match in my second year.
Should I move back to Germany (either directly after I finished my postdoc, or maybe after having stayed for another postdoc, say), will I be able to do the following:
First do a complete rollover of the 403b to a traditional IRA, and then, starting the following fiscal year perform a yearly rollover from the funds in the IRA (with employer matching and possible interest and return of investment) to my existing Roth IRA?
If that is possible, will this rollover be tax-free if I choose a yearly amount that is lower than the yearly personal exemption at that time (this being my only US "income")? Would I have to file taxes as a non-resident alien still in this case?