Claim adjustment reason code
Denial code CO-180 meaning
CARC 180, usually seen as CO-180: The patient has not met the plan's residency requirements.
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- Reason code
- CARC 180
- Short name
- Residency requirement not met
- Plain meaning
- The patient has not met the plan's residency requirements.
- Group codes
- CO-180: 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 lives outside the plan's service area.
What to check before resubmitting
- Check the member's address on file with the plan.
Related reason codes
Related pages
Questions
What does denial code CO-180 mean?
The patient has not met the plan's residency requirements. This is Rivvi's plain-English summary of CARC 180. X12's exact wording is on x12.org.
How do I fix CO-180?
Check the member's address on file with the plan.
Can I bill the patient for CO-180?
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 180?
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.