Quick Guide to CO16 Remark Codes
5 common remark codes for the CO16 denial
by Sarah Hanna

How can providers increase their collection potential? One answer is by decreasing denials. This is easier said than done sometimes if you are not analyzing your denials, following the appropriate protocols to resolve the denial through payment, or providing sufficient training so that the collections team knows how to handle the denial. In this article, I will provide you with tips on working through one of the top denials providers receive. That denial is the CO16—Claim/service lacks information, which is needed for adjudication.

When a CO16 denial is received, the first place to start is by looking at any accompanying remark codes. These remark codes are there to further define what information is missing. If the remark code definitions are not available, the Washington Publishing Company houses complete lists of both Claim Adjustment Reason Codes (denial codes) and Remittance Advice Remark Codes here. Let’s get started by reviewing some of the various remark codes that accompany the CO16.

1: Remark Code M60

This code indicates that a required Certificate of Medical Necessity (CMN) or DME MAC Information Form (DIF) is missing from the claim. Sometimes the issue can be as simple as the CMN not being linked correctly to the claim within the provider’s software. While this would be an obvious omission on the first claim for an oxygen or enteral patient, it could be a less apparent issue if the patient was taken over from a previous supplier and the prior CMN or DIF status was not investigated.

For example, if a Group I oxygen patient is taken over from a previous supplier in the sixth month of rental and there is no break in service, the recertification CMN will be required much sooner than the typical one year span from the initial CMN. Although having the complete information regarding the previous CMN would help prevent the denial, once the denial has been received, it can be easily corrected by resubmitting the claim with the required CMN attached. This is true of whatever type of CMN or DIF is required for the claim. Some providers attempt to resolve this denial through redeterminations or re-openings. However, given the turnaround times for processing those requests, a resubmission that is processed in 14 days is much quicker.

2 / 3: Remark Codes N264 and N575

N264: Missing/incomplete/invalid ordering provider name.

N575: Mismatch between the submitted ordering/referring provider name and records.

A CO16 denial does not necessarily mean that information was missing. It could also mean that specific information is invalid. For example, in 2014, after the implementation of the PECOS enrollment requirement, DMEPOS providers began to see CO16 denials when the ordering physician was not enrolled in PECOS. The N264/N575 remark codes are used to indicate this is the case. Also, something as simple as spelling the ordering physician’s name differently on your claim than how it is displayed in the PECOS enrollment can be cause for denial.

While these denials were prevalent immediately after implementation, they still occur as physicians fail to recertify their enrollment. If this happens, it is important to contact the physician as quickly as possible so he or she can complete recertification. Once this happens, you will be able to resubmit the claim and receive payment.

4: Remark Code M124

If you encounter the M124 remark code on the explanation of benefits, it means that there is a missing indication of whether the patient owns the equipment that requires the part or supply. This could be received in the case of a new fee-for-service Medicare patient that did not have their base equipment billed through Medicare, and the provider is attempting to bill supplies or accessories. Medicare requires in those instances that the following information is added to box 19 on the CMS-1500 form or the NTE field for electronic claims: HCPCS code of the base equipment, a notation that the beneficiary owns the equipment and the date the patient received the equipment. This information would also be required on repair items where Medicare did not pay for the base equipment.

To receive payment on the claim, the base equipment information would need to be obtained, added to the NTE field or box 19 and rebilled to Medicare. As there is limited space available on both box 19 and the NTE field, using approved abbreviations is key to attaching all necessary information.

Noridian Healthcare Solutions has supplied a suggested abbreviations list on their website. Visit them at noridianmedicare.com, choose Jurisdiction D and search for the article titled, “Suggested Abbreviations When Reporting Additional Documentation Notations in the ANSI and NCPDP Formats.”

5: Remark Code N350

Medicare uses the N350 remark when there is a missing/incomplete/invalid description of service for a Not Otherwise Classified Code.

An example of the N350 remark code would be billing an E1399 when the item provided does not meet the definition of an established HCPCS code. When billing for one of these codes, the following information needs to be added to box 19 on the CMS-1500 form for paper claims or the NTE field for electronic claims: Product Name, Make/Model of Item and MSRP. To resolve this denial, the information will need to be added to the claim and rebilled.

For commercial payers, the CO16 can have various meanings. It is primarily used to indicate that some other information is required from the provider before the claim can be processed. It could be used to indicate that an authorization is missing or invalid, that the primary explanation of benefits is missing or invalid, that the correct diagnosis is missing, or even that the payer requires medical records supporting the need for the item the patient has received.

When you receive a CO16 from a commercial payer, as stated above, the first place to look would be at any remark code present on the ERA, paper EOB or even the payer’s website. If the reason for the denial is not detailed enough in a remark code, the next step would be to contact the payer to see what information is required. Once the required information is obtained, make sure you know the method to submit the corrected or missing information for each specific payer. This will differ from one payer to the next. Some payers will be as simple as a resubmission, while others will want a corrected claim or information faxed to them along with a form. Corrected claims may also need to go paper or electronically based on the payer and could have requirements for specific required information in areas on the claim. Ensuring that all of these details are clear with your collectors is important to gaining payment as quickly as possible.