Claim adjustment reason code
Denial code CO-B7 meaning
CARC B7, usually seen as CO-B7: The provider was not certified or eligible to be paid for this service on the date of service.
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- Reason code
- CARC B7
- Short name
- Provider not certified for this service on this date
- Plain meaning
- The provider was not certified or eligible to be paid for this service on the date of service.
- Group codes
- CO-B7: 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 provider's enrollment was not active on the date of service.
- The provider lacks the certification the service needs, such as a CLIA certificate for a lab test.
What to check before resubmitting
- Check the provider's enrollment effective date with the payer.
- For lab tests, check the CLIA certificate type and number.
Remark codes that often come with it
Related reason codes
Related pages
Questions
What does denial code CO-B7 mean?
The provider was not certified or eligible to be paid for this service on the date of service. This is Rivvi's plain-English summary of CARC B7. X12's exact wording is on x12.org.
How do I fix CO-B7?
Check the provider's enrollment effective date with the payer. For lab tests, check the CLIA certificate type and number.
Can I bill the patient for CO-B7?
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 B7?
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.