The Complete Insurance Denial Code Library — What Every Code Means
The ClaimCompass Denial Code Library translates every major insurance denial code and tells you exactly what to do.
Step-by-step guide to appealing a mental health denial — including how to identify and use a parity violation.

Mental health insurance denials occur at rates several times higher than comparable medical claims — despite federal law requiring equal treatment. If your insurer denied coverage for therapy, inpatient care, residential treatment, or any other mental health service, you have strong grounds to appeal.
Your insurer must provide the specific clinical criteria used to deny the claim. Request the complete denial reason and the clinical review criteria applied.
Find a comparable physical health benefit in your plan. Are the prior authorization requirements, visit limits, or coverage criteria more restrictive for mental health? If yes — that is a parity violation under the Mental Health Parity and Addiction Equity Act, and it is one of the strongest grounds for an appeal.
Your treating clinician should provide a letter of medical necessity addressing the specific denial criteria — why the level of care was appropriate, why lower levels of care were tried or are not appropriate, and the clinical consequences of denying coverage.
Your appeal letter should address the parity issue if applicable, cite your physician's clinical documentation, reference published treatment guidelines from organizations such as the American Psychiatric Association, and request a peer-to-peer review with the insurer's medical reviewer.
Insurers frequently approve outpatient therapy but deny in patient, residential, or intensive outpatient levels of care as "not medically necessary." These denials are among the most consistently overturned on appeal when:
ClaimCompass identifies parity violations and generates a formally written mental health appeal letter citing your federal rights and clinical evidence.
Upload your mental health denial at myclaimcompass.ai for a free analysis.