Denial Code 50 (CO-50, PR-50) — Meaning & What to Do
Claim Adjustment Reason Code (CARC)
What denial code 50 means: The insurer decided this service was not medically necessary.
What to do about denial code 50: You can appeal with supporting documentation from your doctor if you believe it was necessary.
CO-50 vs PR-50 vs OA-50: what the prefix means
| Code on your EOB | What the prefix means | Who typically pays |
|---|---|---|
| CO-50 | Contractual obligation — the provider writes the amount off | Usually not the patient |
| PR-50 | Patient responsibility | The patient |
| OA-50 | Other adjustment | Often another payer or plan |
The prefix tells you who is expected to absorb the amount; the number (50) tells you why.
Related codes
CARC 45The charge was above the maximum allowed amount, and the excess was written off.
CARC 55The service is considered experimental or investigational by the plan.
CARC 29The claim was submitted too late (past the filing deadline).
CARC 96This service is not covered by your plan.
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 50
What does denial code 50 mean on my EOB?
The insurer decided this service was not medically necessary.
What should I do about denial code 50?
You can appeal with supporting documentation from your doctor if you believe it was necessary.
Found this code on your bill or EOB?
Upload the document — MD Bill Check decodes every code, checks the math line by line, and explains what's worth questioning.