835 Denial Combination

CO-22

CO

Contractual Obligation · Claim-Level Adjustment

Coordination of Benefits

What This Combination Means

The payer is denying payment because they have determined another insurance carrier should be primary for this service under coordination of benefits rules. The provider must pursue payment from the other identified payer and write off any amounts not recovered from either payer per contractual obligations. The patient cannot be billed for this adjustment.

Financial Responsibility

other payer

Another insurance carrier is responsible for payment as the primary payer. The provider must bill the correct primary payer and can only recover what both payers collectively allow per their contracts.

N/A

Appeal Success

30-60 days (corrected claim cycle)

Avg. Resolution

Medium

Difficulty

No

Appealable

Step-by-Step Resolution

Steps tailored specifically to this CO-22 combination — not generic advice.

Not Appealable:This is a contractual coordination of benefits issue requiring corrected claim submission to the proper payer sequence, not an appeal.
  1. 1

    Verify patient's current coordination of benefits and payer order

    Contact the patient or check eligibility systems to confirm which insurance should be primary for the date of service

  2. 2

    Submit claim to the correct primary payer identified in COB verification

    If another payer is primary, bill them first; if this payer should be primary, submit corrected claim with documentation proving payer order

  3. 3

    Once primary payer processes, submit secondary claim with primary EOB

    Attach the primary payer's remittance to the secondary claim to satisfy coordination of benefits requirements

Specialty Context

How CO-22 typically presents across different practice types.

Dental

Commonly occurs when patients have dual dental coverage (employer and spouse plans) and incorrect payer order was used; verify birthday rule or employment-based primary determination.

Medical

Frequent in scenarios involving Medicare/commercial coordination, workers' compensation overlaps, or when a patient has both group and individual coverage; accurate COB is essential for clean claims.

Behavioral Health

May appear when behavioral health services are covered under both medical and separate behavioral health plans, or when coordination between Medicaid and commercial insurance is required.

Individual Code References

View the standalone definition for each code in this combination.

CARC 22

Medicare Contractor Guidance for CARC 22

FCSO + Noridian + uhc + aetna + bcbs_az

This care may be covered by another payer per coordination of benefits. This denial was received because Medicare records indicate that Medicare is the secondary payer.

How to Prevent CARC 22 Denials

  • ✓

    Ask the patient or patient representative to complete the Medicare Secondary Payer (MSP) Questionnaire to help determine if Medicare is the primary or secondary payer. Place the completed questionnaire in the patient's file.

  • ✓

    Check patient eligibility and verify if Medicare is the secondary payer via SPOT.

CMS IOM Pub. 10-05 Medicare Secondary Payer, Chapter 2SPOTNMP

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Synthesized from official definitions — not from training data

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