How to Appeal a Denied Insurance Claim

A step-by-step appeals guide for mental health therapists.

Behavioral health claims are denied more often than comparable medical claims, yet fewer than 1% of denials are ever appealed, and many are reversible. This guide walks solo and small group mental health practices through the full appeals process, from decoding the denial letter to external review, with copy-and-paste templates you can adapt the same day a denial arrives.

Use this guide to:

• Decode denial letters and match reason codes to the right appeal strategy
• Confirm your appeal deadline and route for employer, state-regulated, Medicare, and Medicaid plans
• Build an evidence file that links diagnosis, functional impairment, and intervention
• Apply parity law to challenge limits that hit mental health benefits harder than medical care
• Escalate to external review, where an independent clinician makes a binding decision
• Adapt seven templates, from letters of medical necessity to regulatory complaints