@roch,
My husband is the patient. He has Original Medicare A&B and BCBS of Calif as secondary(not supplemental) which is has in-network access to Mayo Az(confirmed by member service as well as list of in-network contractors on Mayo website). Our 2ndary is an employer insurance so I'm on the plan as well.

Mayo is submitting the claims to our 2ndary insurance as out-of-network because they are using out-of-network NPIs. Our 2ndary can only process the service as in-network if the provider, uses in-network NPIs. So it's not true that the insurance decides if in-network; it's a contract between the provider and insurance company. The question is why is Mayo billing our 2ndary with out-of-network NPIs.

We(member services and I)had a conference call last week with the billing supervisor last week and she had no response to the question. Billing supervisor said she would look into it but I have yet gotten a response. I've asked the nurse who else we can talk to about this but she has no idea. It's very frustrating when you're not able to speak to the people in charge of processing the claims directly.

If you have Medicare as primary, have you ever had a service denied under Medicare? Do you ever have to sign ABNs which is a Medicare waiver? We are occasionally asked to sign it because Medicare may/may not cover a service. We are dealing now with a situation where Medicare denied a service and the balance is forwarded to our 2ndary and the claim is billed out-of-network. I believe Mayo should re submit the claim to our 2ndary as in-network. I have already spoken to Billing and they had no explanation about the out-of-network billing. I hope to get an explanation from them soon.