Retirement tax questions

If you have already filed your 2020 tax return, you will need to amend it when you received Form 1099-R next year.   However, if you have not filed your 2020 tax return, you can report the earnings before you file which will save you from having to amend it later.   You can enter a substitute Form 1099-R to report the earnings.   Then when you received the form next year, you will enter it and can ignore the message to amend.   The FIT will be correctly applied to the 2021 tax return, but the codes in Box 7 will reference 2020, so the entries will not be applicable to the 2021 return.   If you have already filed the 2020 return, then you should wait and amend when you receive the form next year.   

To use Form 4852 to prepare a substitute Form 1099-R, you go through the Form 1099-R section itself.    Then, check the box showing you need to prepare a substitute Form 1099-R and follow the instructions on the screen.  

@WEK       See the picture below for a visual reference: