To avoid the 50% excess -accumulation penalty, you'll want to make the late distribution in 2022 and report it (along with your 2022 RMD that you'll also take in 2022) on your 2022 tax return. If the 2021 RMD was truly late (because 2021 was not the first year that you were required to take an RMD), after receiving the late 2021 RMD you'll want to include Form 5329 Part IX with your 2021 tax return to request a waiver of the 50% excess-accumulation penalty.
