So the denial is just stating "missing information"? Have you ever had any claims paid? I would have a paper copy of the one that paid, and compare it side by side to one that is denying.
If you don't have any that were paid, I would look for the Medicaid provider manual to see what the instructions are. Since Keystone First is a Medicaid managed health plan, they should follow the Medicaid rules so the provider manual may help.
If you've tried calling but they are not helpful then you will need to try to find out what's wrong another way. I'm not sure if you've called more than one time, but it may be that you had an unhelpful rep. If I get one like that I try back later to get a different rep.
I haven't billed EPSDT myself so I don't have anything specific but that's my ideas.
