Since no RMD was required to be paid to the participant for 2021, no RMD would be payable to a beneficiary attributable to the 2021 distribution calendar year. The post-death RMDs must begin by 12/31 of the year following the year of the participant's death. Based on your facts, the beneficiary would need to commence RMDs by no later than 12/31/2022 with respect to the 2022 account balance.