Birth of child claim denied for out of network hospital

Hello – I got the distressing news today that my insurance company (one of the big 5) denied our claim for the birth of our child 3 weeks ago at one of the biggest hospitals in our city in Virginia. I called our OB a few weeks before the due date and the billing office confirmed that the OB is in network for our plan. Although she is employed by a private group, she only delivers at one hospital, so that is where we had the baby. However, I found out today that the actual hospital is out of network, so despite that provider being in network, almost all of our bill (~$20,000) was denied.

When I look at the EOB, it actually says “provider network status: in network,” but the Cigna person I talked to said this is because they cover behavioral health charges at that hospital, but not medical. She advised me to call the OB’s office to get a letter of support to attach to my appeal. I called the OB’s office, and they said it will have to be handled by the hospital. I called the hospital and they said, “yep that OB is out of network here. There’s nothing else we can do.” The OB office biller seemed to think that the hospital would have a vested interest in helping me with my appeal, but the person I talked to from the hospital had zero interest in helping me and just wanted to get me off the phone. I’m planning to go to the hospital billing office tomorrow to try to talk to a supervisor and if that doesn’t work, I guess file an appeal with the insurance company on my own, but I wanted to check in here and see if you all had any other advice.

I can’t believe that the billers with the OB’s office, with whom we were getting PRENATAL care, didn’t bother to tell us that the only hospital where she delivers doesn’t take our insurance. Any recommended course of action here? What are the chances I get off the hook?