CO 97 Denial Code: What It Means & How to Fix It (2026)

What Does CO 97 Denial Code Mean?

CO 97 (Claim Adjustment Reason Code 97) means: "The benefit for this service is included in the payment/allowance for another service/procedure that has already been adjudicated."

In plain English: the payer says this service is bundled into another service you billed on the same claim. They're paying for the primary service and considering this service already included.

Why You Received CO 97

The payer's claims processing system uses National Correct Coding Initiative (NCCI) edits to identify procedure codes that should not be billed separately. Common reasons include:

• Component/comprehensive bundling — You billed a component procedure separately from the comprehensive procedure that includes it


• Mutually exclusive procedures — Two procedures that normally wouldn't be performed together in the same session


• Same-day duplicate — The payer considers the service a duplicate of another service performed the same day


• Global surgical period — The service falls within the global period of a previous surgery

Common CO 97 Bundling Examples

Example 1: E/M with Procedure

• Billed: 99213 (Office visit) + 11102 (Skin biopsy)


• Denied: 99213 with CO 97


• Why: E/M is bundled into the biopsy unless the visit was separately identifiable


• Fix: Add modifier 25 to the E/M code if the visit was distinct from the biopsy

Example 2: Lab Panels

• Billed: 80053 (Comprehensive metabolic panel) + 82947 (Glucose)


• Denied: 82947 with CO 97


• Why: Glucose is a component of the CMP


• Fix: This is correct bundling — glucose cannot be billed separately with CMP

Example 3: Surgical Procedures

• Billed: 29881 (Knee arthroscopy with meniscectomy) + 29877 (Chondroplasty)


• Denied: 29877 with CO 97


• Why: NCCI edits bundle these together


• Fix: If procedures were performed in different compartments, append modifier 59 or XS

How to Appeal a CO 97 Denial

Step 1: Check NCCI Edits

Look up the code pair on the CMS NCCI Lookup Tool. Check if a modifier is allowed to unbundle.

Step 2: Determine if Modifier is Appropriate

• Modifier 59 (Distinct Procedural Service) — The denied procedure was distinct from the primary procedure (different site, different session, different encounter)


• Modifier 25 (Significant, Separately Identifiable E/M) — The E/M visit was above and beyond the procedure


• XE, XS, XP, XU modifiers — More specific alternatives to modifier 59

Step 3: Resubmit or Appeal

• If modifier was missing → Resubmit as corrected claim with appropriate modifier


• If modifier was already on the claim → Appeal with operative report or clinical notes showing the services were distinct


• If bundling is correct → Do not appeal; the payer is applying NCCI edits correctly

When NOT to Appeal CO 97

Not every CO 97 denial is wrong. Do not appeal if:

• The denied code is truly a component of the comprehensive code


• The services were not performed in distinct anatomical sites or separate sessions


• Adding a modifier would be inappropriate unbundling (which is a compliance risk)

CO 97 vs Related Denial Codes

| Code | Meaning | Key Difference |
|------|---------|----------------|
| CO 97 | Benefit included in another service | Bundling/NCCI edit |
| CO 50 | Not medically necessary | Clinical denial |
| CO 11 | Diagnosis inconsistent | Coding mismatch |
| CO 59 | Processed based on multiple procedure rules | Payment reduction, not full denial |

Prevention Tips

• Check NCCI edits before billing — Use the CMS NCCI Lookup Tool before submitting claims with multiple procedure codes


• Use appropriate modifiers proactively — Add modifier 59/XS when procedures are genuinely distinct


• Document distinctness — Operative reports should clearly document separate sites, sessions, or encounters


• Don't unbundle inappropriately — Incorrect use of modifier 59 is a compliance risk and audit trigger

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Related Denial Code Guides

• Complete CARC & RARC Denial Code Reference Guide


• CO 50 Denial Code Guide — Medical necessity


• CO 11 Denial Code Guide — Diagnosis mismatch


• CO 16 Denial Code Guide — Missing information


• CO 97 Denial Code Guide — Bundling/NCCI edits


• MA01 Remark Code Guide — Medicare COB


• N479 Remark Code Guide — Missing documentation