Insurance Says 'Not Medically Necessary' — What It Really Means and How to Fight It

You opened a letter from your insurance company and read the words: "not medically necessary." Your doctor prescribed it. You need it. But your insurer disagrees.

This is the single most common reason insurers deny mental health claims — and it's also one of the most successfully appealed.

What "Not Medically Necessary" Actually Means

When your insurer says a service is "not medically necessary," they're not saying you don't need treatment. They're saying the specific service, at this specific level, at this specific time doesn't meet their internal criteria.

The important word is their. Insurers write their own medical necessity criteria, and these criteria are often more restrictive than what the actual clinical evidence supports.

Common "not medically necessary" denials in mental health:

• Therapy frequency — "Weekly therapy is sufficient; twice-weekly is not medically necessary"
• Level of care — "Outpatient therapy is appropriate; intensive outpatient (IOP) is not necessary"
• Continued treatment — "You've improved enough; additional sessions are not necessary"
• Medication — "Try a cheaper alternative first" (step therapy)
• Testing — "Neuropsychological testing is not necessary for this diagnosis"

Why These Denials Are Often Wrong

There are three common problems with medical necessity denials:

1. The Reviewer Didn't Examine You

Insurance company medical directors review paper records — they never see the patient. Your treating provider who actually examines you has far more clinical information. Courts have consistently ruled that a treating provider's judgment carries more weight.

2. The Criteria May Violate Parity

If the insurer applies stricter medical necessity criteria to mental health than to medical/surgical conditions, that violates the Mental Health Parity Act. For example, if they require "acute crisis" for mental health authorization but only "functional impairment" for physical health — that's a parity violation.

3. The Clinical Evidence Supports Your Treatment

Professional organizations like the APA (American Psychiatric Association) and AACAP (American Academy of Child and Adolescent Psychiatry) publish treatment guidelines that often support more intensive treatment than insurers want to cover. Peer-reviewed research in journals like JAMA Psychiatry and the American Journal of Psychiatry provides the evidence.

How to Appeal a "Not Medically Necessary" Denial

1. Get Your Insurer's Exact Criteria

You have the right to request the specific clinical criteria they used to make the decision. Ask for:

• The specific medical policy they applied
• The guideline or criteria document they referenced
• The name and credentials of the reviewing physician

2. Get a Letter From Your Provider

Your treating provider's letter should:

• Explain your specific clinical presentation
• Describe what treatments you've tried and how you responded
• Cite clinical guidelines supporting the recommended treatment
• Explain why the insurer's suggested alternative is inadequate for your case
• Address the specific denial reason point by point

3. Find Clinical Evidence

Search for peer-reviewed studies that support your treatment. The best evidence comes from:

• Practice guidelines from APA, AACAP, ASAM
• Randomized controlled trials showing efficacy
• Systematic reviews and meta-analyses
• Studies published in high-impact journals (NEJM, JAMA, Lancet)

Each study should be cited with full reference including the PMID number (PubMed ID), which the insurer can independently verify.

4. Challenge Their Criteria

In your appeal letter, argue:

• The treatment meets generally accepted standards of medical practice
• The insurer's criteria are more restrictive than clinical guidelines
• Comparable medical/surgical conditions are held to less restrictive standards (parity argument)
• The patient's individual clinical circumstances warrant this treatment

5. Request Peer-to-Peer Review

Before or after filing your written appeal, request a peer-to-peer review — this is a direct conversation between your treating provider and the insurer's medical director. Many denials are overturned at this stage because the insurer's reviewer hears clinical details that weren't in the written records.

The Numbers Are on Your Side

The data is clear:

• 83% of medical necessity denials are overturned on appeal (AMA)
• 52% of denied claims are overturned with properly formatted appeal letters with legal citations
• Less than 1% of denied patients actually appeal

Most insurers' denial systems are designed for volume, not accuracy. They rely on automated criteria matching and brief physician reviews. A detailed, evidence-based appeal forces them to actually engage with your clinical situation — and when they do, the denial often doesn't hold up.

Let Evidence Do the Talking

Gathering clinical evidence, understanding parity law, and writing a professional appeal letter is a lot of work. Overturn handles it in minutes:

1. Upload your denial letter
2. We analyze it against clinical guidelines and parity law
3. We search PubMed for peer-reviewed evidence supporting your treatment
4. You receive a professional appeal letter ready to send

Your doctor said you need it. The clinical evidence supports it. Federal law protects it. Make your insurer prove otherwise.