Enter the 2021 1099-R on your 2020 amended return as a 2021 1099-R as you have the option to choose. The Box 2a amount is taxable for 2020, and that is why you need to amend your 2020 return.
You also need to enter the 2021 1099-R on your 2021 tax return because there is federal income tax withheld. The $200 in box 2a will be added to your 2020 gross income.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"