Claim adjustment reason code
Denial code OA-133 meaning
CARC 133, usually seen as OA-133: The claim or service is on hold for more review.
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- Reason code
- CARC 133
- Short name
- Pending further review
- Plain meaning
- The claim or service is on hold for more review.
- Group codes
- OA-133: Other adjustment. An adjustment that is neither the provider's nor the patient's, often from coordination of benefits.
Plain-English summary written by Rivvi. X12 owns the CARC list and its exact wording, which is not reproduced here. Read it on the X12 CARC list (list dated November 1, 2025, checked October 23, 2026). This page does not decide how a claim is paid.
Common causes
- The payer is reviewing the claim, for example for records or a medical review.
What to check before resubmitting
- Wait for the final decision. Answer any records request quickly.
Related reason codes
Related pages
Questions
What does denial code OA-133 mean?
The claim or service is on hold for more review. This is Rivvi's plain-English summary of CARC 133. X12's exact wording is on x12.org.
How do I fix OA-133?
Wait for the final decision. Answer any records request quickly.
Can I bill the patient for OA-133?
With group code CO, no. CO means the provider absorbs the amount under its contract or the payer's rules.
Which group codes come with CARC 133?
Most often OA (other adjustment). The group code, not the reason code, says who owes the amount.
What is the difference between a CARC and a RARC?
A claim adjustment reason code (CARC) says why a claim line was paid differently than billed. A remittance advice remark code (RARC) adds detail, such as which field is missing.