Do not change the code in box 7. Both should have code 4. (TurboTax treats code 4 the same as code 7 when the beneficiary is the spouse of the decedent.) Simply split the amounts in boxes 1 and 2a between two 1099-R forms in TurboTax, indicating one is RMD and the other reports a distribution that was rolled over. (If any amount was withheld for taxes, you can allocate that to the 1099s, reporting on the 1099-R for the RMD no more withholding than the gross amount reported on that form and any withholding beyond that on the 1099-R for the rollover.
