# CO 96 Denial Code: Not Covered Charges and What to Do Next

> CO 96 means the payer treats the charge as not covered. Read the remark code, check the plan benefits and decide between an appeal and a corrected claim.

Source: https://webillhealth.com/co-96-denial-code/  
Publisher: WeBill Health  
Last updated: November 4, 2026

Denial code

## CO 96 denial code, answered before it ages

CO 96 means the payer treats this charge as not covered. Check the plan, then appeal or correct.

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

A CO 96 denial says the payer considers the charge not covered. The remark code printed beside it explains the restriction, and your next move depends on what that remark code says about the service.

* What CARC 96 says
Non-covered charge(s). [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)
* Liability without an ABN
Medicare may hold the provider financially liable if the patient was not given an ABN where one was required. [CMS, ABN tutorial](https://www.cms.gov/Outreach-and-Education/Medicare-Learning-Network-MLN/MLNProducts/ABN-Tutorial/formCMSR131tutorial111915f.html)
* Appeal window
Medicare first level appeals are due within 120 days of receiving the initial determination, and late requests need good cause. [CMS, redetermination](https://www.cms.gov/medicare/appeals-grievances/fee-for-service/first-level-appeal-redetermination-medicare-contractor)
* Late appeals
Medicare first level appeals are not accepted past the 120 day redetermination date unless good cause qualifies. [CGS Medicare, When to appeal](https://cgsmedicare.com/partb/appeals/when.html)

## In the official words

> Non-covered charge(s)

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

> Claims submitted with a GA modifier: must submit a valid signed ABN

[CGS Administrators, LLC](https://cgsmedicare.com/partb/appeals/when.html)

## Read the remark code before you decide

CARC 96 requires at least one remark code, and that remark code holds the reason. One pairing is N130: Consult plan benefit documents/guidelines for information about restrictions for this service. It sends you to the plan documents, not to a coding fix. [X12 reason codes](https://x12.org/codes/claim-adjustment-reason-codes) [X12 remark codes](https://x12.org/codes/remittance-advice-remark-codes)

For Medicare, an Advance Beneficiary Notice (ABN) is what moves financial responsibility to the patient when a covered service is expected to be denied. CMS says it may hold the provider financially liable when a required ABN was not given. [CMS, ABN tutorial](https://www.cms.gov/Outreach-and-Education/Medicare-Learning-Network-MLN/MLNProducts/ABN-Tutorial/formCMSR131tutorial111915f.html)

## How to clear a CO 96 denial

1. Pull the remark code for the line from the 835 or the paper remit.
2. Check the plan benefit documents for the service, the diagnosis and the date of service.
3. If the line only needs a minor correction, Noridian points to a reopening request. CMS says contractors do not take minor error corrections through the appeals process.
4. If the service should have been covered, send records that support it with an appeal. CGS says a claim submitted with a GA modifier has to carry a valid signed ABN.
5. For Medicare, the first level appeal is due within 120 days of receiving the initial determination, and CMS presumes receipt 5 calendar days after the notice date. A late request needs good cause.
6. If the service was truly not covered, check whether a valid ABN was on file before you decide who carries the balance, and log the cause.

The appeal window and the reopening route come from CMS and Medicare contractor guidance. [CMS, redetermination](https://www.cms.gov/medicare/appeals-grievances/fee-for-service/first-level-appeal-redetermination-medicare-contractor) [CMS, Claims Processing Manual chapter 29](https://www.cms.gov/regulations-and-guidance/guidance/manuals/downloads/clm104c29.pdf) [CGS Medicare](https://cgsmedicare.com/partb/appeals/when.html) [Noridian, Timely Filing](https://med.noridianmedicare.com/web/jfb/topics/claim-submission/timely-filing)

## Stop CO 96 before it starts

Coverage denials can often be seen before the claim leaves: the service against the plan, the diagnosis against the policy and the notice requirements for the payer. Those are checks a claim can pass in advance.

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, ABN tutorial](https://www.cms.gov/Outreach-and-Education/Medicare-Learning-Network-MLN/MLNProducts/ABN-Tutorial/formCMSR131tutorial111915f.html)
* [CMS, redetermination](https://www.cms.gov/medicare/appeals-grievances/fee-for-service/first-level-appeal-redetermination-medicare-contractor)
* [CGS Medicare, When to appeal](https://cgsmedicare.com/partb/appeals/when.html)
* [x12.org, remittance advice remark codes](https://x12.org/codes/remittance-advice-remark-codes)
* [cms.gov, clm104c29](https://www.cms.gov/regulations-and-guidance/guidance/manuals/downloads/clm104c29.pdf)
* [med.noridianmedicare.com, 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 96 or clear the same way.

* [CO 16](https://webillhealth.com/co-16-denial-code/)
* [CO 197](https://webillhealth.com/co-197-denial-code/)
* [PR 204](https://webillhealth.com/pr-204-denial-code/)

See every code on [Denial Codes Explained: What Each Means and How to Clear It](https://webillhealth.com/denial-codes/). When the same denial keeps returning, read the [Denial Root Cause Playbook](https://webillhealth.com/denial-root-cause-playbook/).

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=dermatology) 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/