I inherited a 401k and an IRA from my father this year. I received a 1099-R for both accounts because I was required to take an RMD for my father for 2019. Both forms had a distribution code of 4 - Death. When I entered the info for the IRA 1099-R it had checked the IRS/SEP/Simple box and TurboTax treated it as an inherited IRA and prompted for additional info. The 401k 1099-R does not have IRS/SEP/Simple checked and because of the distribution code 4 - Death, treated it as if I had died (This Person). How do I enter this so the 401k is treated as inherited?
Code 4 means that the distribution was paid to you as beneficiary of your father, not that you died. "This person" means your father.
The portion of your father's RMD that you completed after his death is taxable to you.