If you are a non-spouse beneficiary of a distribution from an IRA, took a distribution that was intended to be an RMD, returned that distribution to the IRA and you have already indicted to TurboTax that this distribution was an RMD, you'll need to delete the 1099-R from TurboTax an reenter it, making sure to indicate that it was not an RMD. Even though the distribution was originally intended to be an RMD, because RMDs for 2020 were waived, the distribution is not actually an RMD.
