Mastering CO-226 and MA81 Denials in Medical Billing

Maximizing Appeal Success: Decoding CO-226 and MA81 Denial Codes


 Providers often face obstacles and end up with denied claims – sometimes by the nefarious CO-226 or MA81 denial codes. Knowing what they mean and how to successfully appeal these denials is imperative for keeping your practice-management software from overflowing with codes that cause Medicare enrollees to delay care.

CO-226: Unraveling the Insufficient Information Conundrum

Denial Reason Breakdown

 CO-226 signifies inaccurate information provided by the billing – or rendering – provider; the CERT billing contractor notes lack of conformance to Medicare requirements in the medical records of practitioners.

Resolution Strategies

 As for CO-226 denials, in order to make that correction, the provider should review the claim once they receive the adjustment notice and initiate the claim adjustment. Palmetto GBA then has to claw back the overpayment. A physician who feels that the CO-226 denial is incorrect can file a request for a redetermination (appeal) by writing to Palmetto within 120 days of receiving the remittance advice notice.

MA81: Confronting the Signature Challenge

Deciphering Denial Reasons

 MA81 means no, incomplete or invalid signature of a provider or supplier. The supposed technical nature of the denial code serves only to highlight the need of reports and orders in a practitioner’s medical record to be accompanied by extremely precise signatures, including X-rays.

Strategic Resolutions

 MA81 denials should be handled proactively: adjusters should get in front of claim adjustments and recoup any overpayments. And, if an adjudication is done in error, the next step is redetermination – practitioners need to contact Palmetto GBA in writing within 120 days. 

Absence of Valid Orders/Requisitions/Documentation of ‘Intent’

Understanding CO-226 in Specific Contexts

 We see CO-226 come back when analysing the denial of orders, requisitions and documentation of ‘intent’. The CERT review contractor searches instances in which ‘intent’ has not been established or fully documented according to Medicare requirements.

Tactical Resolutions

 Providers receiving CO-226 denials in the context of claims and orders or requisitions must act with haste. Claim adjustments will be made and overpayments must be recovered. Redetermination is the only recourse, with practitioners submitting a written appeal to Palmetto GBA within 120 days. 

N455 and N456: Navigating Missing Physician Orders

N455: The Challenge of Missing Orders

 N455 codes for ‘not otherwise specified’ – ie, no physician order – and CO-226 codes for ‘Other specified diagnoses’, reasons for denials. Because of these code deficiencies, providers must pay close attention when dealing with the appeal process. 

N456: Confronting Incomplete/Invalid Orders

 In other words, N456 enumerates instances where the physician order is ‘inadequately specified’ or ‘not in writing’, and CO-226 serves as an explanatory code for the DME denial.
‘The best chance you have at a successful appeal is if you follow through every line in the [ denial] letter. You cannot even miss one entry. It’s like an attorney’s brief. Once, I even called the carrier to verify that the coverage was active and they said “No, your physician never provided proof of medical necessity”’ she explained.


 Denials of CO-226 and MA81 are inescapable, but knowing how to appeal them gives providers an advantage. Having first-hand knowledge of these denial codes, as well as the insider’s approach to successful appeals, will bolster their reimbursements – and their position relative to the demands of Medicare compliance.