CO-163
Attachment/other documentation referenced on the claim was not received
What This Code Means
The claim referenced supporting documentation (e.g. operative notes) that the payer never received.
Common Causes
- Attachment not actually transmitted with the claim
- Fax/upload to the payer's system failed silently
How to Resolve or Appeal
- Confirm what documentation the payer expects
- Resend the attachment through the payer's preferred method and track confirmation of receipt
Educational reference only — not medical or legal advice. Always confirm code usage and appeal rights with the specific payer.