The CO stands for Contractual Obligation, so that means that the disallowed amount is going to be a provider contractual obligation and is not billable as patient responsibility. However, this may be a resolvable issue based on CARC 185 indicating: The rendering provider is not eligible to perform the service billed." and RARC N570 indicates: "Missing/incomplete/invalid credentialing data."
Is the credentialing paperwork with the payer denying claims CO185/N570 absolutely complete? Based on the N570 there is something wrong/incomplete with the provider's credentialing information. In my mind it makes sense the payer denied the claim CO185 because if the credentialing is incomplete the payer does not have the information necessary to determine if the rendering provider is eligible to perform the services billed.
If I were working this denial, I would find out from the payer what the status of the provider's credentialing paperwork is, and they should be able to tell you what if anything is missing or incomplete in the provider's paperwork. If the provider representative indicates that the provider's credentialing paperwork is complete, verify the date it was completed if the provider was eligible to render the services to patients covered by the payer.
I work for an insurance company and it our standard processing guidelines for completing the credentialing processing, assuming all of the necessary information was submitted, is 60 days. The provider's effective date as an eligible provider is based on when the credentialing process was completed, not the date the paperwork was submitted. Typically, the effective date is not retroactively effective to a date prior to completion of the credentialing process, unless an error was made on our end. It is not uncommon for us to receive claims for services rendered prior to the provider being credentialed and those services are typically denied and if the provider is contracting with us the claims are denied as a provider contractual obligation, if the provider is noncontracting then the services are denied as patient responsibility.
If the provider representative with the payer at issue here indicates that the provider was properly credentialed for the date of service of the denied claim, I would ask them to reconsider the claim denial. If they are upholding the denial find out why the claim being denied since CO185 & N570 should not be applicable, unless the provider is acting outside the scope of their license for the state where services are being rendered. It could also be that the payer doesn't cover the type of provider for the services rendered, for instance a Certified Surgical Assistant (CSA) is not covered by Medicare for reimbursement for assistant surgeon services.
In the interim you should not be billing the patient for these services, so the sooner you contact the payer to find out why CO185 & N570 were used to deny the claim and get it resolved the sooner you can possibly get reimbursed for these services.