A 2020 code "P" means "taxable in 2019". You must enter the 2020 code P 1099-R into an amended 2019 tax return and TurboTax will ask if it is a 2019 or 2020 1099-R - select 2020 and then the box 2a amount will go on the amended 2019 1040 line 4b.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
