Claim adjustment reason code
Denial code CO-116 meaning
CARC 116, usually seen as CO-116: The advance notice the patient signed (an ABN for Medicare) did not meet the requirements.
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- Reason code
- CARC 116
- Short name
- Patient notice did not meet the rules
- Plain meaning
- The advance notice the patient signed (an ABN for Medicare) did not meet the requirements.
- Group codes
- CO-116: 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 ABN was missing details, signed late, or used the wrong form version.
What to check before resubmitting
- Use the current CMS-R-131 ABN form with the item, reason and estimated cost filled in.
- The provider writes off the amount when the notice is not valid.
Related reason codes
Related pages
Questions
What does denial code CO-116 mean?
The advance notice the patient signed (an ABN for Medicare) did not meet the requirements. This is Rivvi's plain-English summary of CARC 116. X12's exact wording is on x12.org.
How do I fix CO-116?
Use the current CMS-R-131 ABN form with the item, reason and estimated cost filled in. The provider writes off the amount when the notice is not valid.
Can I bill the patient for CO-116?
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 116?
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.