Pro fee billing/documentation requirements

Elkhart, IN
Best answers
I work for a system and am looking for clarification regarding pro fee billing. The hospital has "series" patients that span 60 days. Our bill goes out for the entire span therefore all codes documented during the series go on one bill. If the patient had dehydrations documented on March 2, then anemia on March 10th during a series both codes would be billed.
We are being told that the physicians cannot bill that way. They bill for each separate DOS. So they would submit a bill for dehydration for March 2 and a separate bill for March 7th. While, in theory, I believe this is correct, but I am struggling finding the documentation to prove it.

Would anyone know a resource/manual I can refer to in order to confirm this?

Thank you!