Tax Year Prior to 2020: Box 12, code P Non-Military

[Sup_Dalek]

When I tried to enter information for box 12 with code P I got an error. 

Turbo tax says this is for only allowed for military personnel, but the back of my W2 does not mention that this code applies only to the military.

Who is correct?

[KarenL]

The software is correct.  This is new with the 2018 Tax Reform changes.  From 2018 through 2025 , moving expenses are now only allowed to be deducted in the case of military personnel who were ordered to move to a new permanent station.  Please see this FAQ about How Tax Reform Will Affect Your 2018 Taxes.