CO — Contractual obligation — the provider absorbs it and cannot bill the patient.
So the balance cannot move to the patient. Either the appeal recovers it or the practice absorbs it. That makes the appeal decision the whole decision on this line.
The same code, a different prefix. 55 also arrives as PR 55. The reason for the denial is the same. The prefix decides who pays for it, so the next step is not the same. If your remit says PR 55, read that page instead.
Winnable with a clinician. Recoverable on the merits, but somebody clinical has to attest.
Appeal with literature and the payer policy. Low win rate; triage by dollar value.
Where this comes from. This is our own reading of the code, not the payer's and not a copy of the standards text. We classify it from how these denials actually resolve. Where we are unsure, we say so rather than guessing.
Send your denial summary for the last ninety days. Four columns: payer, CARC code, count, billed amount. I will tell you which were winnable and what they were worth.
Send your denial summary No patient data. No BAA. No charge.