CO 97 denial code

Claim adjustment reason code 97. Often reported as CO 97.

Service included in another payment

Unofficial reference. This is our own plain-English explanation, not the official code text. Payer rules differ. Verify with the payer and the official X12 code list. AlphaPrefix is not affiliated with X12, CMS or any payer. Data last updated Nov 11, 2026.

What 97 means

No separate payment was made because the payer counts this service as part of another service or procedure already paid.

This is the bundling denial. The payer considers the line to be part of a larger service, a global surgical package, or an evaluation and management visit already paid on this claim or an earlier one. The money for it is treated as included in that other payment.

With group code CO, the amount is normally a provider adjustment and is not moved to the patient. A policy reference at the service line may name the edit or payment policy used. Fixes usually involve a correct modifier, separate documentation, or showing that the services were truly distinct.

Group codes seen with 97

On a remittance, 97 comes after a group code. These are the ones it is most often reported with:

• CO 97 (Contractual Obligation): The provider's side of the ledger. The reduction comes from the payer contract or a rule the provider has to follow, and the patient normally cannot be billed for it.

The payer chooses the group code for each adjustment, so the same reason code can appear with another group code on your remittance. Read the two together. More about group codes.

Common causes

• The procedure is a component of a more comprehensive procedure billed on the same date.
• The service falls inside a global surgical period for a procedure already paid.
• An evaluation and management visit was billed on the day of a procedure without the right modifier.
• Supplies or minor services are bundled into the facility or procedure payment under the payer's policy.
• A line was billed on a separate claim even though it belongs with a service already paid.

What to do next

1. Identify the service the line was bundled into, using the remark codes and policy reference on the remittance.
2. Check the payer's bundling edits and the global period for the primary procedure.
3. If the services were separate and distinct, correct the claim with the proper modifier and documentation.
4. If the bundling is correct, post the line as a contractual adjustment per the group code and contract.
5. Appeal with the operative or visit notes when the edit was applied in error.

Related codes

• 4 (reason code) Procedure code and modifier do not match
• 45 (reason code) Charge exceeds the allowed amount
• 96 (reason code) Service not covered by the plan
• 16 (reason code) Missing information or billing error