What CO-11 means
The payer does not accept the linked diagnosis as a reason for this service.
The CO group code means this amount is a contractual obligation: under most contracts you cannot bill it to the patient.
Common causes
- Wrong diagnosis pointer on the service line
- Diagnosis not supported by payer policy for the service
How to fix it
- Check the diagnosis linked to each line
- Code to the documentation and the payer's coverage policy, then correct the claim
Check the remark code (RARC) that came with the denial and the payer's own policy, since rules vary by payer and plan. This is a plain-English summary written by GetMax; the official code text is published by X12 at x12.org/codes.
Prevent it next time
Most denials are caused before the claim is sent. See 12 ways to reduce claim denials, or let our denial management team work them for you.