CO-234 Denial Code: Procedure Not Paid Separately
The CO-234 denial code means this procedure is not paid separately - its payment is packaged into another service or payment on the claim. Payers are required to send a remark code with it explaining the specific packaging rule, so the RARC on the remit tells you which bundling policy applied. A frequent Medicare pairing is remark code M2 (not paid separately when the patient is an inpatient).
Common Causes
- Services packaged under facility payment systems (inpatient stays, outpatient packaging rules) rather than paid fee-for-service
- A professional service billed separately while the patient was an inpatient and the payment belongs in the facility claim
- Ancillary services (supplies, some drugs, add-on services) whose payment is packaged into the primary procedure's rate
- Billing the professional and technical components separately in a setting where only the global or facility payment applies
How to Fix CO-234
- Read the remark code accompanying CO-234 - it names the packaging rule (for example, M2 for inpatient packaging)
- Verify the patient's status (inpatient vs outpatient) on the date of service and bill under the correct payment system
- If the service is packaged, the denial is correct - post the adjustment; do not bill the patient
- If the patient status or setting on the claim was wrong, correct it and resubmit
- For split professional/technical billing, confirm which component you are entitled to bill in that setting
Frequently Asked Questions
CO-234 means the procedure is not paid separately - payment for it is packaged into another service or payment system. The remark code sent with it identifies the specific packaging rule; M2 (not paid separately when the patient is an inpatient) is a common companion.
CO-97 says the benefit is included in another adjudicated service, typically through bundling edits like global periods. CO-234 is about payment packaging - the service is never paid on its own in this setting, most often because facility payment already covers it.
Only if the claim misrepresented the situation - wrong patient status, wrong setting, or a service that is genuinely separately payable in that context. If the packaging rule applies as billed, the correct action is posting the contractual adjustment.
Related Denial Codes
Related Resources
Claim adjustment reason codes and remittance advice remark codes are standardized code sets maintained by X12. The explanations on this page are written in our own words for educational purposes, based on public CMS and Medicare contractor documentation. Payer policies vary - always confirm handling with the specific payer's guidance and your contracts.