Appealing a Medicaid (generic) CO-22 Denial
A Medicaid (generic) CO-22 denial (coordination of benefits) is one of the most common claim rejections behavioral health therapists face. This guide explains exactly what caused the denial and the most effective appeal strategy for behavioral health practices.
What this denial means
The payer believes another insurer should pay first. This triggers when a patient has multiple insurance plans and the primary/secondary sequence was not established or was submitted out of order.
Your appeal strategy
Verify the patient's COB information and confirm which plan is primary. Submit the EOB from the primary payer with the secondary claim. If your payer is primary but coded the claim as secondary, provide the COB letter or member insurance card showing your payer's priority status.
What Medicaid (generic) requires
30 calendar days (Level-1 appeal)
90 days from Level-1 denial
Medicaid rules vary substantially by state and managed-care organization (MCO). Under the ACA, states must cover mental health and SUD services as essential health benefits. State fair-hearing rights apply (42 CFR § 431.200). Specific appeal addresses depend on the MCO (Molina, Centene/WellCare, Aetna Better Health, etc.).
Generate your Medicaid (generic) CO-22 appeal letter
First 5 letters free. No credit card. Editable draft in about 60 seconds.
Generate my appeal letter →Frequently asked questions
How long does Medicaid (generic) have to respond to a CO-22 appeal?
Under federal regulations and most state prompt-payment laws, Medicaid (generic) must respond to a Level-1 internal appeal within 30 calendar days. If you receive an adverse determination, you typically have 90 calendar days from the date of the Level-1 denial to request external review. Send the appeal via certified mail or through the payer's portal and keep documentation of the submission date. Note: these timelines are best-effort estimates — verify current deadlines directly with the payer.
Does MHPAEA apply to CO-22 denials?
CO-22 denials are not directly tied to mental health parity protections in most cases — this code is a general adjudication rule that applies equally to all claim types. MHPAEA may still be relevant if the underlying reason for the denial differs for mental health vs. medical/surgical services. When in doubt, include a parity argument in your appeal.
Can I appeal a CO-22 denial more than once?
Yes. Most payers, including Medicaid (generic), allow at least two levels of internal appeal (Level-1 and Level-2 or "expedited" review). After exhausting internal appeals, you have the right to request an Independent Medical Review (IMR) or external review through your state insurance commissioner. Keep copies of every appeal, submission confirmation, and payer response.
What documentation do I need to appeal a CO-22 denial from Medicaid (generic)?
At minimum: the original Explanation of Benefits (EOB) or Remittance Advice (RA) showing the CO-22 denial, the original claim details (CPT code, date of service, NPI, charge amount), and any clinical documentation supporting medical necessity. Submit everything in one packet with a cover letter citing the specific denial code, the date of service, and the claim number.