Denial codes / CO-22
CO-22 denial: meaning, fix & appeal letter template
Payer thinks another plan should pay first.
What it means
Official CARC 22 descriptionThis care may be covered by another payer per coordination of benefits.
The payer's coordination-of-benefits (COB) records show another active plan that should be primary. Often the patient's COB record is out of date with the payer rather than the claim being wrong.
Common causes
- Patient has (or had) another plan the payer lists as primary
- Outdated COB questionnaire on file with the payer
- Medicare Secondary Payer situation (employer coverage, liability, workers' comp)
- Primary EOB not attached to the secondary claim
- Dependent covered by both parents' plans (birthday rule)
How to fix it
- Verify all active coverage with the patient and through eligibility (270/271)
- Ask the patient to update COB with the payer (many require the member to call)
- If another plan is primary, bill it first, then send the secondary claim with the primary EOB
- If this payer is primary, send proof (termination letter, COB update confirmation)
- Resubmit once the payer's COB record is updated
Appeal or corrected claim?
Update COB, then resubmit — rarely an appeal. Most CO-22s clear once the member updates COB or the primary EOB is attached. Use a reconsideration letter when you have proof the other coverage was terminated or this payer is primary.
What to attach
- Primary payer EOB/remittance (if billing as secondary)
- Proof of termination of the other coverage
- Member COB update confirmation or questionnaire
CO-22 appeal letter template
Replace every [BRACKETED] field. Remove any optional paragraph that doesn't apply.
[PRACTICE NAME] [ADDRESS] · [PHONE] · NPI [NPI] · TIN [TIN] [DATE] [PAYER NAME] Attn: Appeals / Provider Disputes [PAYER APPEALS ADDRESS] Re: Request for Reconsideration — Claim [CLAIM NUMBER] Patient: [PATIENT NAME] Member ID: [MEMBER ID] DOB: [DOB] Date of Service: [DOS] CPT: [CPT CODE] Billed: [AMOUNT] Denial: CO-22 — This care may be covered by another payer per coordination of benefits. Dear Appeals Reviewer, We request reconsideration of the denial of the above claim. The above claim was denied with CARC 22, indicating the service may be covered by another payer. [PAYER NAME] is the primary payer for this patient on the date of service: [REASON — e.g. the patient's coverage with [OTHER PLAN] terminated on [DATE] / the member has no other active coverage]. Enclosed is [termination letter / updated COB confirmation dated [DATE]]. We request the claim be reprocessed as primary. Based on the enclosed documentation, we request that [PAYER NAME] overturn this denial and reprocess the claim for payment in accordance with the member's benefits and our participation agreement. Enclosures: - Primary payer EOB/remittance (if billing as secondary) - Proof of termination of the other coverage - Member COB update confirmation or questionnaire Please contact [CONTACT NAME] at [PHONE] or [EMAIL] with any questions. Sincerely, [NAME], [TITLE] [PRACTICE NAME]
Stop writing these off — get a free denial audit
Send us your CO-22 denials (and the rest). DenialIQ's agents read each one, pull the payer policy, and draft an appeal like this for your team to approve.