WellCare Medicare Adv Primary, Fidelis secondary

[Denises08]

I'm brand new to billing. I'm in NY state as a Physical Therapy office biller and I'm having trouble with this particular patient. Wellcare medicare advantage plan primary, then fidelis PICC Long Term is secondary. Question Number 1, Will a Medicaid Managed plan pay after a Medicare advantage plan? Number 2, if secondary will pay, how do I bill it? Wellcare accepts many CPT codes and we don't typically bill 97530 (as accepted by Fidelis), so do I need to go into my system and change each dos to 97530 with the previously billed fees after wellcare denies or is there a better way?