Claim adjustment reason code
Denial code CO-252 meaning
CARC 252, usually seen as CO-252: The payer needs an attachment or other records to decide this claim.
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- Reason code
- CARC 252
- Short name
- Attachment needed
- Plain meaning
- The payer needs an attachment or other records to decide this claim.
- Group codes
- CO-252: 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 needs records by payer policy, such as an operative note or invoice.
What to check before resubmitting
- Read the remark code for which record is needed.
- Send it with the claim control number.
Remark codes that often come with it
Related reason codes
Related pages
Questions
What does denial code CO-252 mean?
The payer needs an attachment or other records to decide this claim. This is Rivvi's plain-English summary of CARC 252. X12's exact wording is on x12.org.
How do I fix CO-252?
Read the remark code for which record is needed. Send it with the claim control number.
Can I bill the patient for CO-252?
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 252?
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.