A code "P" indicates that you had an excess 2015 deferral returned in 2016. That is taxable in 2015 which will require an amended 2015 tax return to report it.
https://ttlc.intuit.com/questions/1894381-how-to-amend-change-or-correct-a-return-you-already-filed
https://ttlc.intuit.com/replies/3288565
**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.**
