CO-97 Denial Code: Service is bundled into another procedure's payment

What CO-97 means

CO-97 means the service was bundled into another line on the same or a related claim. Most often it reflects a National Correct Coding Initiative (NCCI) Procedure-to-Procedure edit, where one code is considered a component of a more comprehensive code. Sometimes the bundling is correct; sometimes a distinct service was wrongly bundled and an appropriate modifier (such as 59 or an X{EPSU} modifier) would unbundle it when the documentation supports a separate, distinct service.

Common causes

• An NCCI Procedure-to-Procedure edit treats this code as a component of another code billed the same day.
• Two services were genuinely part of one global package (for example, within a surgical global period).
• A distinct, separately identifiable service was billed without the modifier needed to indicate it.
• Incorrect code selection that overlaps with a more comprehensive code already paid.

How to fix it

• Check whether an NCCI PTP edit pairs the two codes and whether the edit allows a modifier (modifier indicator 1) to override it.
• If documentation supports a separate, distinct service, resubmit a corrected claim with the appropriate modifier (59 or X{EPSU}) and supporting notes.
• If the bundling is correct, post the write-off. CO is contractual and cannot be billed to the patient.
• If billed during a surgical global period, confirm whether a modifier (such as 24, 25, or 79) applies.

How to prevent it

• Scrub claims against current NCCI PTP edits before submission so bundled pairs are caught up front.
• Train coders on when modifier 59 / X{EPSU} is and is not supported by documentation. Overuse triggers audits.
• Verify global-period rules before billing related services around a procedure.

Appeal letter template

Fill in the bracketed fields, attach your supporting documentation, and send through the payer's appeal channel. This is a starting point — adjust to your payer's requirements.

Re: Appeal of Bundling Denial (CO-97) - Claim [Claim Number]

Patient: [Patient Name]   |   Member ID: [Member ID]
Date(s) of Service: [DOS]   |   Codes at issue: [CPT A] and [CPT B]

To Whom It May Concern:

CPT [CPT B] was denied under CO-97 as included in CPT [CPT A]. These services were separate and distinct: [briefly describe the distinct service - different site/session/encounter]. Per the documentation enclosed, modifier [59 / XS / XE / XP / XU] is appropriate. [Confirm the NCCI edit for this pair carries a modifier indicator of 1 (modifier override allowed) before submitting.]

We request that CPT [CPT B] be reprocessed and paid as a distinct procedural service. The operative/procedure note is enclosed.

Sincerely,
[Your Name], [Practice Name]   |   [Phone]   |   [NPI/TIN]