Claim adjustment reason code
Denial code CO-155 meaning
CARC 155, usually seen as CO-155: The claim shows the patient refused the service.
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- Reason code
- CARC 155
- Short name
- Patient refused the service
- Plain meaning
- The claim shows the patient refused the service.
- Group codes
- CO-155: Contractual obligation. The provider absorbs the amount under its contract or the payer's rules. Do not bill the patient for it.
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 service was billed even though the patient refused it.
What to check before resubmitting
- Check the record and correct the claim.
Related pages
Questions
What does denial code CO-155 mean?
The claim shows the patient refused the service. This is Rivvi's plain-English summary of CARC 155. X12's exact wording is on x12.org.
How do I fix CO-155?
Check the record and correct the claim.
Can I bill the patient for CO-155?
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 155?
Most often CO (contractual obligation). 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.