What CO-A1 means
A general denial. A remark code on the remittance explains the reason.
The CO group code means this amount is a contractual obligation: under most contracts you cannot bill it to the patient.
Common causes
- Varies: see the RARC
How to fix it
- Read the RARC and act on the specific reason
- Call the payer if the reason is unclear
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.