easiest one to remember is 'PAID' (if you see the "medco" logo anywhere on the ID, use this planID)
always search by BIN then PCN, and find the plan ID with the description that best matches the card.
If the PT is a Medicare Part D member, look for "MPD" towards the end of the planID.
Defintily make a little cheat sheet to carry around, eventually you'll memorize all the common ones that are local to your region. 😉