Insurance & cost
Why your insurance might deny "medical necessity" and how to appeal
You've been told you need residential treatment. Your clinician agrees. But your insurance company denies the claim, saying it doesn't meet "medical necessity" criteria. This is one of the most common — and most frustrating — barriers to treatment. Here's how it works and what you can do.
What 'medical necessity' means to insurers
Insurance companies use clinical criteria — often based on ASAM (American Society of Addiction Medicine) guidelines or proprietary systems like InterQual — to determine whether a requested level of care is "medically necessary." In theory, these criteria ensure appropriate care. In practice, they're frequently used to justify denying higher (more expensive) levels of care. A common scenario: your clinician recommends residential treatment, but the insurance company says IOP is "sufficient" based on their criteria review.
Why denials happen
Denials often come down to documentation. The treating clinician may not have included sufficient clinical detail in the authorization request. The reviewer may not have full context about your history, previous treatment attempts, or co-occurring conditions. Sometimes the denial is simply a cost management strategy — the first denial is automatic, and many patients give up without appealing.
How to appeal: The process
Step 1: Request the denial in writing. You have the right to a written explanation including the specific criteria used. Step 2: Ask your treatment provider to submit a peer-to-peer review — this is a phone call between your treating clinician and the insurance company's medical reviewer. This often resolves the denial. Step 3: If the peer-to-peer fails, file a formal internal appeal. Include additional clinical documentation, letters from your provider, and relevant medical records. Step 4: If the internal appeal fails, file an external appeal with your state's insurance department. An independent reviewer evaluates the case. Many states have online filing systems that make this straightforward.
Know your rights
The Mental Health Parity and Addiction Equity Act requires insurers to cover mental health and substance use treatment at the same level as physical health conditions. If your insurance covers 30 days of inpatient medical care, it cannot impose a lower limit on inpatient behavioral health care. If you believe parity is being violated, file a complaint with your state insurance commissioner and with the federal Department of Labor (for employer-sponsored plans).