No, you cannot just change your 2021 Form 8606. You will have to correct the previous Forms 8606.
You can correct Form 8606 on standalone basis if the changes won't affect the rest of the return. Otherwise, you will have to amend your tax returns.
Please see Form 8606 and Instructions.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"
