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.
Seeing denial code 50 on your EOB?
A denial code tells you what the payer reported, but it may not tell the whole story. Reviewing your EOB and bill together can help clarify what may need attention.
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
- What Is an Itemized Medical Bill? How to Request One
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.
Seeing this code on your own EOB?
Upload the EOB, the bill, or both — MD Bill Check reads the codes on your documents, compares them side by side, and flags what's worth questioning. Free, no account needed.