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.
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
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.
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.