How do I resolve a CO-16+N179 denial?

Identify what information the payer requested from the member: Contact the payer to understand what specific information was requested from the member and why a billing error triggered a member inquiry rather than a provider request. Contact the member/patient to ensure they respond to the payer's request: Proactively reach out to the patient to confirm they received the payer's information request and assist them in understanding what needs to be provided to avoid claim abandonment. Monitor for automatic reconsideration after member response: Track the claim for automatic reprocessing once the payer receives member information; if no update occurs within 45 days of member response, contact payer to request manual reconsideration.

835 Denial Combination

CO-16+N179

Contractual Obligation · Claim-Level Adjustment

Missing Information

What This Combination Means

The payer has identified missing information or billing errors on the claim and is requesting additional information directly from the patient/member rather than the provider. The CO group code indicates this is a contractual write-off at present, but the claim will be reconsidered once the payer receives the requested information from the member. This is an unusual combination where the provider's billing error has triggered a member-directed information request.

Financial Responsibility

provider writeoff

The provider must write off this amount under contractual obligation while awaiting the payer's receipt of information from the member. If the member provides the requested information and the claim is reconsidered favorably, the payer may reprocess and pay.

N/A

Appeal Success

30-60 days (dependent on member response)

Avg. Resolution

Medium

Difficulty

Appealable

Step-by-Step Resolution

Steps tailored specifically to this CO-16+N179 combination — not generic advice.

Not Appealable:CO adjustments for submission errors are contractual write-offs and not appealable, though the claim may be reconsidered automatically once the member provides information to the payer.

1
Identify what information the payer requested from the member
Contact the payer to understand what specific information was requested from the member and why a billing error triggered a member inquiry rather than a provider request.
2
Contact the member/patient to ensure they respond to the payer's request
Proactively reach out to the patient to confirm they received the payer's information request and assist them in understanding what needs to be provided to avoid claim abandonment.
3
Monitor for automatic reconsideration after member response
Track the claim for automatic reprocessing once the payer receives member information; if no update occurs within 45 days of member response, contact payer to request manual reconsideration.

Specialty Context

How CO-16+N179 typically presents across different practice types.

Dental

May occur when dental claims require patient attestation of coordination of benefits or confirmation of dependent status that was not properly documented on the original claim submission.

Medical

Common when claims involve secondary payer situations, medical necessity questionnaires, or patient consent forms that the payer requires directly from the member due to incomplete provider submission.

Behavioral Health

May arise when behavioral health claims require patient confirmation of out-of-network provider choice, treatment consent acknowledgment, or verification of referral details that were improperly documented by the provider.

Individual Code References

View the standalone definition for each code in this combination.

CARC 16 RARC N179

Medicare Contractor Guidance for CARC 16

FCSO + Noridian + uhc + aetna + bcbs_az

This RUC is received when a claim is submitted with missing, incorrect, or invalid information. For details pertaining to your claim, please refer to the remittance advice remark codes (RARCs) on the remittance advice (RA).

How to Prevent CARC 16 Denials

✓
Review the RARC on the remittance advice to identify which specific field has the error.
✓
Per Medicare guidelines, claims must be filed no later than 12 months after the date of service. RUCs are not considered filed/submitted.

CMS guidelines for completion of form CMS-1500 in the Medicare Claims Processing Manual (100-04), Chapter 26SPOTFee Schedule Lookup ToolCMS laboratory demographics lookupModifier lookup toolNoridian Medicare PortalNMPIVRSame or SimilarPECOSPDAC

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Synthesized from official definitions — not from training data

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