Is an amended return needed for the 2021"
I recommend using 1040-X to submit 8606.
Note: when you are not changing any dollar amounts on your amended tax return, you can leave all the lines 1-23 EMPTY.
Do not include your old 1040 nor your revised 1040 because the Form 1040-X reflects any changes there and becomes your new tax return.
using this method you sign 1040-X not 8606.
