Claim adjustment reason code
Denial code OA-101 meaning
CARC 101, usually seen as OA-101: This is an estimate from a predetermination, not a payment. Payment comes after the service is done and billed.
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- Reason code
- CARC 101
- Short name
- Predetermination estimate
- Plain meaning
- This is an estimate from a predetermination, not a payment. Payment comes after the service is done and billed.
- Group codes
- OA-101: 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
- A predetermination request was sent before the service.
What to check before resubmitting
- Bill the claim after the service is done.
Related pages
Questions
What does denial code OA-101 mean?
This is an estimate from a predetermination, not a payment. Payment comes after the service is done and billed. This is Rivvi's plain-English summary of CARC 101. X12's exact wording is on x12.org.
How do I fix OA-101?
Bill the claim after the service is done.
Can I bill the patient for OA-101?
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 101?
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.