Denial Code 133 (CO-133, PR-133) — Meaning & What to Do
Claim Adjustment Reason Code (CARC)
What denial code 133 means: The service is still under review (not final).
What to do about denial code 133: Wait for the final decision before paying.
CO-133 vs PR-133 vs OA-133: what the prefix means
| Code on your EOB | What the prefix means | Who typically pays |
|---|---|---|
| CO-133 | Contractual obligation — the provider writes the amount off | Usually not the patient |
| PR-133 | Patient responsibility | The patient |
| OA-133 | Other adjustment | Often another payer or plan |
The prefix tells you who is expected to absorb the amount; the number (133) tells you why.
Related codes
CARC 132A prearranged demonstration-project adjustment was applied.
CARC 136The claim failed a required 'present on admission' indicator check.
CARC 131A negotiated or contractual discount was applied.
CARC 137A regulatory penalty or fee was applied.
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 133
What does denial code 133 mean on my EOB?
The service is still under review (not final).
What should I do about denial code 133?
Wait for the final decision before paying.
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