Appeal letter template: another payer is primary (CO-22)
For denials asserting other coverage is primary. Resolves the payer's coordination-of-benefits record, which is usually what is actually wrong.
Free, no signup required to read or copy it. Replace every bracketed field before sending, and refer to the patient by initials and account reference only — never a full name.
Use this when
- The remittance shows CO-22 or states care may be covered by another payer.
- There is no other coverage, and the payer's file is out of date.
- The other coverage terminated before the date of service.
- The primary payer has already adjudicated and you are billing as secondary.
The letter
[PRACTICE NAME] [PRACTICE ADDRESS] [PHONE] · [FAX] [DATE] [PAYER NAME] — Appeals Department [APPEALS ADDRESS FROM YOUR REMITTANCE] RE: Appeal of claim denial Claim number: [CLAIM NUMBER] Patient reference: [PATIENT INITIALS] / [ACCOUNT REFERENCE] Date of service: [DATE OF SERVICE] Billed amount: [AMOUNT] Denial code: CO-22 — care may be covered by another payer per coordination of benefits To the Appeals Department: We are appealing the denial of the claim identified above, which was denied pending coordination of benefits. [CHOOSE THE PARAGRAPH THAT MATCHES YOUR SITUATION AND DELETE THE OTHERS] [IF THERE IS NO OTHER COVERAGE] Eligibility verification obtained on [VERIFICATION DATE] shows your plan as the only coverage in effect on the date of service. We are not aware of any other coverage applicable to this patient for this episode. We ask that the coordination-of-benefits record be updated and the claim processed. [IF THE OTHER COVERAGE TERMINATED] The coverage your record identifies as primary terminated on [TERMINATION DATE], before the date of service. Documentation is attached. We ask that the claim be reprocessed with your plan as primary. [IF THE PRIMARY HAS ALREADY PAID] The primary payer has adjudicated this claim. Its remittance, dated [PRIMARY REMITTANCE DATE], is attached and shows an allowed amount of [PRIMARY ALLOWED] and payment of [PRIMARY PAID]. We ask that this claim be processed as secondary in accordance with that determination. We understand that coordination-of-benefits records are often updated by the member directly. If information is still outstanding from the member, we ask that you identify what is required so we can assist in obtaining it. Attached in support of this appeal: [LIST ATTACHMENTS — eligibility verification, primary remittance, termination documentation] We ask that you reprocess this claim and remit payment in the amount of [AMOUNT]. Please provide a written determination within your stated appeal-response window. If any additional documentation would assist the review, contact me directly at [PHONE] or [EMAIL]. Sincerely, [NAME] [TITLE] [PRACTICE NAME] [NPI / TAX ID]
How to adapt it
- Ask what the payer still needs. These denials frequently persist because the member has not returned a coordination-of-benefits questionnaire, and no documentation from the practice resolves that.
- Attach the primary remittance whenever one exists — it converts the appeal from an argument into a routine secondary adjudication.
- Keep the primary payer's remittance date on file regardless: it is your defense if a timely filing denial follows.
Understand the denial first
CO-22CO-22 denial: another payer is primaryThe payer thinks someone else is primary and wants that payer to process the claim first.Common questions
- Why does this denial keep coming back?
- Usually because the payer is waiting on the member, not on you. Coordination-of-benefits questionnaires go to the patient, and until one is returned the record stays unresolved no matter what the practice sends.
- Should I bill the patient in the meantime?
- No. CO-22 is a contractual adjustment, and unresolved coverage order does not make the balance the patient's responsibility.
Or skip the blanks entirely
Undeny reads the denial document, fills every one of these fields from it, and tracks the appeal deadline. About three minutes instead of thirty.