CO-197 Denial — How to Appeal for Behavioral Health
CO-197 (precertification / authorization absent) is one of the most common insurance denial codes behavioral health therapists encounter. This guide explains what triggered the denial and the most effective appeal strategy across all major payers.
What CO-197 means
The payer is denying because no prior authorization was obtained before services were rendered. This is one of the most contested denial codes in behavioral health because payers often require authorization for mental health visits when comparable medical/surgical outpatient visits require no authorization.
MHPAEA Mental Health Parity Argument
Requiring prior authorization for outpatient mental health services when comparable medical/surgical outpatient services do not require authorization is an NQTL that violates MHPAEA (29 CFR § 2590.712(c)(4)). Under CAA 2021 § 203 the plan must produce, on request, a written comparative analysis showing the authorization standard is applied no more restrictively to mental health than to medical/surgical care — that statutory disclosure duty was unaffected by the 2025 federal non-enforcement of the 2024 Final Rule.
Request your payer's written Non-Quantitative Treatment Limitation (NQTL) comparative analysis. They are required to provide it under CAA 2021 § 203.
Appeal strategy for CO-197
Appeal by invoking MHPAEA: document whether the payer requires prior authorization for comparable outpatient medical services (e.g. physical therapy, specialist visits). If no authorization is required for medical care but is required for therapy, this is a parity violation. Request the payer's NQTL comparative analysis in writing. Also check whether state law imposes any carve-out for emergency mental health services that bypasses authorization requirements.
CPT codes commonly denied with CO-197
Appeal CO-197 by payer
Select your payer for appeal address, deadline, and payer-specific MHPAEA notes.
Generate your CO-197 appeal letter in 60 seconds
First 5 letters free. No credit card. MHPAEA arguments included when applicable.
Generate my appeal letter →Frequently asked questions about CO-197
What does CO-197 mean on a behavioral health claim?
The payer is denying because no prior authorization was obtained before services were rendered. This is one of the most contested denial codes in behavioral health because payers often require authorization for mental health visits when comparable medical/surgical outpatient visits require no authorization.
How do I appeal a CO-197 denial?
Appeal by invoking MHPAEA: document whether the payer requires prior authorization for comparable outpatient medical services (e.g. physical therapy, specialist visits). If no authorization is required for medical care but is required for therapy, this is a parity violation. Request the payer's NQTL comparative analysis in writing. Also check whether state law imposes any carve-out for emergency mental health services that bypasses authorization requirements.
Does MHPAEA apply to CO-197 denials?
Yes. Requiring prior authorization for outpatient mental health services when comparable medical/surgical outpatient services do not require authorization is an NQTL that violates MHPAEA (29 CFR § 2590.712(c)(4)). Under CAA 2021 § 203 the plan must produce, on request, a written comparative analysis showing the authorization standard is applied no more restrictively to mental health than to medical/surgical care — that statutory disclosure duty was unaffected by the 2025 federal non-enforcement of the 2024 Final Rule. Request the payer's written Non-Quantitative Treatment Limitation (NQTL) comparative analysis under CAA 2021 § 203 — that statutory disclosure duty applies regardless of the 2025 federal non-enforcement of the 2024 Final Rule.
Which insurers most commonly issue a CO-197 denial?
All major commercial payers — Aetna, Cigna, Anthem, UnitedHealthcare, Humana, and BCBS plans — use CO-197. Government programs (Medicare, Medicaid, TRICARE) also issue this code. The appeal strategy is similar across payers, but deadlines and submission addresses vary. Select your payer from the list below for payer-specific instructions.