That is basically the subject of next week’s column, which will be posted soon!
But two things: First, if you took your 2020 RMD in JANUARY 2020, you cannot return it! Just a weird quirk in the rules that says any RMDs taken after Feb 1st can be returned. Experts are hoping that will be revised in subsequent legislation. And if they withheld taxes (assuming you did your RMD after Feb !) you can’t get them back — but they will apply to next year’s tax liability.
Second, this once-a-year rollover limitation applies only from IRA to IRS, or Roth to Roth.
Rollovers from traditional plans such as 40l(k), 403(b) or 457 TO AN IRA do not have that
limitation. So go right ahead — but wait a few days for my column re details!