Claim adjustment reason code
Denial code CO-236 meaning
CARC 236, usually seen as CO-236: This procedure, or procedure and modifier pair, does not go with another one billed on the same day, under NCCI or a state workers' compensation rule.
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- Reason code
- CARC 236
- Short name
- Procedure or modifier pair not compatible
- Plain meaning
- This procedure, or procedure and modifier pair, does not go with another one billed on the same day, under NCCI or a state workers' compensation rule.
- Group codes
- CO-236: 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
- An NCCI edit pairs this code with another one billed on the same day.
- The modifier that would bypass the edit is missing or not allowed.
What to check before resubmitting
- Check the NCCI procedure-to-procedure edit and its modifier indicator.
- Add 59 or an X modifier only when the service was distinct and documented.
Remark codes that often come with it
Related reason codes
Related pages
Questions
What does denial code CO-236 mean?
This procedure, or procedure and modifier pair, does not go with another one billed on the same day, under NCCI or a state workers' compensation rule. This is Rivvi's plain-English summary of CARC 236. X12's exact wording is on x12.org.
How do I fix CO-236?
Check the NCCI procedure-to-procedure edit and its modifier indicator. Add 59 or an X modifier only when the service was distinct and documented.
Can I bill the patient for CO-236?
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 236?
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.