Claim adjustment reason code
Denial code CO-288 meaning
CARC 288, usually seen as CO-288: The plan needed a referral that is not on file.
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- Reason code
- CARC 288
- Short name
- Referral missing
- Plain meaning
- The plan needed a referral that is not on file.
- Group codes
- CO-288: 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 patient's plan requires a primary care referral for the specialist.
What to check before resubmitting
- Get the referral and its number from the primary care provider.
- Add it to the claim and resubmit.
Related reason codes
Related pages
Questions
What does denial code CO-288 mean?
The plan needed a referral that is not on file. This is Rivvi's plain-English summary of CARC 288. X12's exact wording is on x12.org.
How do I fix CO-288?
Get the referral and its number from the primary care provider. Add it to the claim and resubmit.
Can I bill the patient for CO-288?
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 288?
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.