Denial Code 186 (CO-186, PR-186) — Meaning & What to Do
Claim Adjustment Reason Code (CARC)
What denial code 186 means: A level-of-care change adjustment was applied.
What to do about denial code 186: Ask the provider's billing office to explain or correct this, and resubmit if needed.
CO-186 vs PR-186 vs OA-186: what the prefix means
| Code on your EOB | What the prefix means | Who typically pays |
|---|---|---|
| CO-186 | Contractual obligation — the provider writes the amount off | Usually not the patient |
| PR-186 | Patient responsibility | The patient |
| OA-186 | Other adjustment | Often another payer or plan |
The prefix tells you who is expected to absorb the amount; the number (186) tells you why.
Seeing denial code 186 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 185The rendering provider isn't eligible to perform this service.
CARC 187This relates to a consumer-spending-account (like an HSA/FSA) payment.
CARC 183The referring provider isn't eligible to refer this service.
CARC 188This product/procedure is only covered when used with another service.
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 186
What does denial code 186 mean on my EOB?
A level-of-care change adjustment was applied.
What should I do about denial code 186?
Ask the provider's billing office to explain or correct this, and resubmit if needed.
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.