CO-97 Denial Code: Service Bundled Into Another Service
Many services are considered included in a more comprehensive procedure. The National Correct Coding Initiative (NCCI) procedure-to-procedure edits and global surgery rules define most of these relationships. CARC 97 means the payer applied one of them to this line.
The group code (CO, PR, OA, PI) tells you who is responsible. The CARC number tells you why.
CO-97 means the payer considers this service part of another procedure it already paid, so it is not separately payable. Check whether an NCCI edit or a global surgical period applied. If the service was truly distinct and documented, a corrected claim with the right modifier can fix it.
Common causes of CO-97.
- NCCI procedure-to-procedure edit between two codes on the same date
- Evaluation and management service billed during a global surgical period without modifier 24, 25, or 57
- Incidental supplies or services billed separately
- Distinct procedure billed without the modifier that shows it was separate
How to work a CO-97 denial.
The order matters: confirm the facts before deciding between a corrected claim, a reconsideration, or an adjustment.
- 1Look up the code pair in the NCCI edit tables and check the modifier indicator (0 means no modifier allowed, 1 means a modifier may apply).
- 2If the service fell in a global period, check whether it was unrelated to the surgery.
- 3If documentation shows a separate, distinct service, submit a corrected claim with the appropriate modifier (for example 25, 59, or an X modifier).
- 4If the edit applies and the service was not distinct, accept the bundling adjustment.
How to keep CO-97 from coming back.
- Scrub claims against NCCI edits before submission
- Train coders on correct modifier 25 and 59 use
- Track global periods for surgical patients
Fixing this at the source usually sits with medical coders →
Questions about CO-97.
Denials that often travel with this one.
CO-236: Procedure or Modifier Combination Not Compatible
CO-236 means two procedures or modifiers billed on the same day are incompatible under NCCI or state rules. How to check the edit and correct the claim.
Read about CO-236 →CO-4: Procedure Code Inconsistent With Modifier
CO-4 means the modifier on the claim is missing, invalid, or does not fit the procedure code. Common causes, how to correct the claim, and how to prevent it.
Read about CO-4 →CO-45: Charge Exceeds Contracted or Allowed Amount
CO-45 is a contractual adjustment, not a denial: the charge exceeded the allowed amount. How to post it correctly and when to check for an underpayment.
Read about CO-45 →Add a Dedicated Denial Specialist
RCM Staff places trained denial management specialists inside your EHR and clearinghouse to work the queue, correct and appeal claims, and track root causes by payer.
Kevin Jamito has 18+ years of U.S. healthcare revenue cycle management experience across billing, coding, practice management, and offshore RCM operations. He founded RCM Staff to give U.S. healthcare teams dedicated Philippines-based specialists who work inside their existing systems.