# CO 97 Denial Code: Bundled Services and When They Pay

> CO 97 means the payer bundled a service into another one already paid. Check the NCCI edit, then decide between a write off and a corrected claim.

Source: https://webillhealth.com/co-97-denial-code/  
Publisher: WeBill Health  
Last updated: November 4, 2026

Denial code

## CO 97 denial code: unbundle only what is payable

CO 97 means the payer bundled this service into another. Some bundles are final; others clear with the right modifier.

[Request a Revenue Defense Audit](https://webillhealth.com/revenue-defense-audit/request/)

A CO 97 denial says the payment for this service is already counted inside another service the payer has processed. Sometimes that is correct and the line is a write off. Sometimes the two services were distinct, and the claim pays once it shows that.

* What CARC 97 says
The benefit for this service is included in the payment/allowance for another service/procedure that has already been adjudicated. [X12 reason codes](https://x12.org/codes/claim-adjustment-reason-codes)
* Group code CO
Contractual Obligation. [X12 group codes](https://x12.org/codes/claim-adjustment-group-codes)
* Medicare bundling edits
When both codes of a procedure to procedure pair are billed for one patient on one day, the column two code denies unless a clinically appropriate modifier is reported. [CMS, NCCI PTP edits](https://www.cms.gov/medicare/coding-billing/national-correct-coding-initiative-ncci-edits/medicare-ncci-procedure-procedure-ptp-edits)
* Modifier indicator
Indicator 0 allows no NCCI modifier, 1 allows one when appropriate, and 9 means no active edit. [CMS MLN, How to use the NCCI tools](https://www.cms.gov/Outreach-and-Education/MLN/Educational-Tools/MLN901346-How-to-use-the-Medicare-NCCI/ncci-medicare/chapter_2_using_the_ncci_tools/)
* Where to appeal or reopen
A denied Medicare claim goes to a reopening request for a minor clerical error, or to an appeal with documentation to dispute the decision. [Noridian, Timely Filing](https://med.noridianmedicare.com/web/jfb/topics/claim-submission/timely-filing)

## In the official words

> The benefit for this service is included in the payment/allowance for another service/procedure that has already been adjudicated

[X12](https://x12.org/codes/claim-adjustment-reason-codes)

> …the Column Two code is denied unless a clinically appropriate NCCI PTP-associated modifier is also reported

[Centers for Medicare & Medicaid Services](https://www.cms.gov/medicare/coding-billing/national-correct-coding-initiative-ncci-edits/medicare-ncci-procedure-procedure-ptp-edits)

## Check the edit before you add a modifier

For Medicare, bundling edits come from the National Correct Coding Initiative procedure to procedure tables. CMS says those edits prevent inappropriate payment of services that should not be reported together. [CMS, NCCI PTP edits](https://www.cms.gov/medicare/coding-billing/national-correct-coding-initiative-ncci-edits/medicare-ncci-procedure-procedure-ptp-edits) Every code pair in the tables carries a modifier indicator. With indicator 0, no modifier will get the second code paid, and only the Column 1 code is paid for the same patient on the same day. With indicator 1, a modifier can be used when appropriate. Indicator 9 means there is no active edit for the pair. [CMS MLN](https://www.cms.gov/Outreach-and-Education/MLN/Educational-Tools/MLN901346-How-to-use-the-Medicare-NCCI/ncci-medicare/chapter_2_using_the_ncci_tools/)

A modifier belongs on the claim only when it is clinically appropriate and the documentation shows a distinct service.

## How to clear a CO 97 denial

1. Find the service the payer bundled this line into. It is usually another line on the same claim or a claim already paid for the same date.
2. Look up the code pair in the [CMS procedure to procedure tables](https://www.cms.gov/medicare/coding-billing/national-correct-coding-initiative-ncci-edits/medicare-ncci-procedure-procedure-ptp-edits), or in the commercial payer’s own bundling policy. CMS publishes separate practitioner and hospital tables, and modifiers and pairs may differ between them.
3. If the indicator is 0, the bundle stands. Correct the claim only if a code itself was wrong.
4. If the indicator is 1 and the record documents a separate service, correct the claim with the right modifier. For a denied Medicare claim, Noridian points to a reopening request for a minor clerical error and to an appeal with documentation to dispute the decision. For other payers, use their own correction process.
5. Log the code pair so the same combination is checked before the next claim goes out. CMS posts new edit files every quarter, so check the current ones.

[Noridian, Timely Filing](https://med.noridianmedicare.com/web/jfb/topics/claim-submission/timely-filing) [CMS, NCCI PTP edits](https://www.cms.gov/medicare/coding-billing/national-correct-coding-initiative-ncci-edits/medicare-ncci-procedure-procedure-ptp-edits)

## Stop CO 97 before it starts

Bundling denials follow the code pairs your specialty bills most, which makes them predictable. WeBill Health maintains internal payer rule libraries organized by specialty and by carrier, built and updated by people who work claims in your specialty every day. Every claim receives Human Expert Review against them before it goes out.

## Sources

* [X12 reason codes](https://x12.org/codes/claim-adjustment-reason-codes)
* [X12 group codes](https://x12.org/codes/claim-adjustment-group-codes)
* [CMS, NCCI PTP edits](https://www.cms.gov/medicare/coding-billing/national-correct-coding-initiative-ncci-edits/medicare-ncci-procedure-procedure-ptp-edits)
* [CMS MLN, How to use the NCCI tools](https://www.cms.gov/Outreach-and-Education/MLN/Educational-Tools/MLN901346-How-to-use-the-Medicare-NCCI/ncci-medicare/chapter_2_using_the_ncci_tools/)
* [Noridian, Timely Filing](https://med.noridianmedicare.com/web/jfb/topics/claim-submission/timely-filing)

## Denial Defense 2.0

Root cause denial work that closes the documentation gaps behind repeat denials before they disrupt your revenue cycle.

**98%**

clean claim rate

**40%**

A/R reduction within 90 days

**500+**

payer rulesets in our rule libraries

[See Denial Defense 2.0](https://webillhealth.com/denial-defense-2-0/)

## Related denial codes

These codes often appear beside CO 97 or clear the same way.

* [CO 16](https://webillhealth.com/co-16-denial-code/)
* [CO 4](https://webillhealth.com/co-4-denial-code/)
* [CO 45](https://webillhealth.com/co-45-denial-code/)

See every code on [Denial Codes Explained: What Each Means and How to Clear It](https://webillhealth.com/denial-codes/). To see how your denial rate compares, read [2026 Denial Benchmarks](https://webillhealth.com/2026-denial-benchmarks/).

Reviewed by [Tyler Nguyen](https://webillhealth.com/tyler-nguyen/), Denial Defense Manager, on November 4, 2026. Facts verified November 1, 2026.

## Find the denials that keep coming back

The Revenue Defense Audit is a free, forensic review of your claims and A/R by the team that would work your account. It maps your denial patterns by payer and code, with the root cause behind each one.

[Check my Revenue Defense Score](https://webillhealth.com/revenue-defense-score/?specialty=orthopedics) for the denial exposure in your specialty.

[Request a Revenue Defense Audit](https://webillhealth.com/revenue-defense-audit/request/)

WeBill Health is a specialty focused revenue cycle management partner for independent practices. Request a Revenue Defense Audit at https://webillhealth.com/form/