I have been trying to get claims processed for two health provider bills that are not covered by my insurance. It took several months, multiple denials and conversations with four different OneExchange agents before I got the right answer. It turns out there can be absolutely no reference to "insurance" anywhere on the provider bill.
In the case of the doctor services, I tried to submit evidence of doctor service and fees by using a uniform insurance form my doctor has always given to me. He does not "accept" any insurance and requires payment by the client. However, he does provide a bill on this form with diagnostic codes so the client can submit a claim to insurance for reimbursement (should it be a covered service). Since he accepts no insurance - he obviously has opted out of Medicare. Because I provided that form to OneExchange as evidence of my doctor bill they immediately denied the claim. The claim denial said they wanted to see a copy of the insurance denial. They wanted a "pure" doctor bill on the doctor's stationary to remove that requirement.
I found this out because I recently submitted a bill from my dentist. The dentist forgot I no longer had insurance and sent the claim to MetLife. Of course, it was denied. Then the dentist sent me a bill showing a claim had been sent to MetLife and $0 had been paid. That line item caused OneExchange to deny my dental reimbursement claim because they again wanted to see the dental insurance claim denial. When I called OneExchange to complain, the agent told me there can be no reference to insurance on the bill. So, I whited out the line about MetLife and resubmitted the dentist statement. Voila. The claim was paid.
I complained to the agent that there was no way for me to know this "rule". The agent said it is on the website. Mea Culpa. I didn't read the entire website before submitting claims. Of course, the denial reason couldn't explain that the reference to potential insurance coverage is the reason for the denial. I mean, that is a lot to ask.