What CO-16 means
The claim was missing information or had a submission error. A remark code (RARC) on the remittance says what is missing.
The CO group code means this amount is a contractual obligation: under most contracts you cannot bill it to the patient.
Common causes
- Missing or invalid data such as NPI, address, referring provider or dates
How to fix it
- Read the RARC to find the exact problem
- Fix the data and submit a corrected claim (a new claim if the payer treats it as unprocessable)
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.