CO-226: Information requested from the Billing/Rendering Provider was not provided or not provided timely or was insufficient/incomplete.
The payer previously asked your practice for additional information, such as records, itemization, or clarification, and either did not receive it, received it too late, or received something incomplete.
What the group code means
- CO
- Contractual Obligation. The provider is responsible and the amount cannot be billed to the patient.
Why it fires
- The payer sent a request for records or additional data that was never responded to
- The response was sent after the payer's deadline for submission
- The documentation sent did not fully answer what was requested, such as partial chart notes instead of the complete encounter
Corrective actions, ranked
- 1
Locate the original request
Find the payer's letter or portal request to see exactly what was asked for and the deadline given.
- 2
Submit complete documentation now
Send the full, specific documentation requested as soon as possible, even if the original deadline passed, since many payers will still reprocess.
- 3
Fix the internal request-tracking process
If requests are being missed, set up a tracking log or work queue specifically for payer information requests so none fall through.
Is it worth appealing
Appeal by submitting the complete requested documentation with a cover letter noting the response. This is often resolved with paperwork rather than a substantive appeal argument.
Other denial codes to check
Codes that share a remark code with this one, or that are reported under the same group code.
- CO-45Charge exceeds fee schedule/maximum allowable or contracted/legislated fee arrangement.
- CO-97The benefit for this service is included in the payment/allowance for another service/procedure that has already been adjudicated.
- CO-16Claim/service lacks information or has submission/billing error(s).
- CO-11The diagnosis is inconsistent with the procedure.
- OA-18Exact duplicate claim/service (Use only with Group Code OA except where state workers' compensation regulations requires CO)
- CO-29The time limit for filing has expired.
Retrieved 2026-07-18.
Do not let this happen again
Scrub the claim against NCCI PTP and MUE edits before you submit, free and in your browser.
Denial7 provides billing and administrative guidance based on published CMS and X12 sources. It is not medical advice, not a coverage determination, and not a guarantee of payment. NCCI and MUE edits are republished quarterly and payer policies vary by contract. Always confirm against the payer's own current policy before submitting or appealing.