Denial Code 77 (CO-77, PR-77) — Meaning & What to Do
Claim Adjustment Reason Code (CARC)
What denial code 77 means: This is a covered service, but the charge is the patient's responsibility.
What to do about denial code 77: Confirm this matches your plan's cost-sharing before paying.
CO-77 vs PR-77 vs OA-77: what the prefix means
| Code on your EOB | What the prefix means | Who typically pays |
|---|---|---|
| CO-77 | Contractual obligation — the provider writes the amount off | Usually not the patient |
| PR-77 | Patient responsibility | The patient |
| OA-77 | Other adjustment | Often another payer or plan |
The prefix tells you who is expected to absorb the amount; the number (77) tells you why.
Related codes
CARC 76Payment was already made for this service under another claim.
CARC 94Payment made was more than the charge, creating a credit.
CARC 59Charges were adjusted based on multiple or concurrent procedure rules.
CARC 95The provider billed in a way that doesn't follow the plan's rules.
Keep reviewing your bill
- Medical Bill vs EOB: What Is the Difference?
- How to Dispute a Medical Bill — Find Billing Errors Before You Pay
Frequently asked questions about Denial code 77
What does denial code 77 mean on my EOB?
This is a covered service, but the charge is the patient's responsibility.
What should I do about denial code 77?
Confirm this matches your plan's cost-sharing before paying.
Found this code on your bill or EOB?
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