We are a family practice office with 3 MD's and a PA. The PA always has a supervising doctor present. Is it best practice to bill under the supervising doctors credentials using the SA mod or under the PA's credentials? For Medicare we bill using her credentials to avoid incident to rules and realize there is a reduction in her payments. I have her credentialed with most insurance companies but they all vary as to how much they reduce her payments so i'm thinking of going back and just billing under her supervisor rather then her own credentials except for Medicare. Can anyone with alot of experience billing for PA services give the the best way to handle this? Thanks for your help!