Psychiatric Medication, Practically

"Not Medically Necessary": Decoding the Denial Letter

Save

Few phrases on a denial letter cause as much confusion as 'not medically necessary,' partly because it sounds like a verdict on your health rather than a match against a specific written checklist. This article decodes what the phrase means, how to get the criteria document behind it, and how these denials commonly get reversed.

Last updated: July 2026

Talk to a clinician

Gale can help you find a clinician in your state and request a visit.

Find care →

What does 'not medically necessary' actually mean?

On a denial letter, 'not medically necessary' is a specific, technical finding: the plan's reviewers compared what your prescriber submitted against a written internal standard for that medication and concluded the submission didn't demonstrate the standard was met. It is not a general statement that the medication won't help you, and it usually isn't made by the physician who actually treats you. In practice, this finding is issued more often because of what was or wasn't documented in the request than because of a genuine clinical disagreement about your diagnosis. That distinction matters because it means the fix is frequently about documentation, not about the medication itself. Plans are required to have a documented, disclosable process behind coverage decisions like this one 1.

What criteria did the plan actually apply?

Every plan bases a medical-necessity denial on a written internal policy specific to that medication or class, which typically lists the diagnosis codes, prior treatment history, and clinical measures it's looking for before approving coverage. These criteria are not secret, but they also aren't usually printed in full on the denial letter itself, which is part of why the letter can feel vague. The letter should at minimum name which criteria weren't satisfied, and you're entitled to ask for the specific policy document in full. Mental health parity rules also require that the criteria and process used for a behavioral health medication be comparably rigorous to those used for physical health medications, which is worth knowing if the denial seems to apply a stricter standard than you'd expect 2.

How do you get the criteria document?

Ask your plan directly, by phone or in writing, for the specific medical necessity criteria used to deny this prior authorization or claim, and ask for it in writing rather than a verbal summary 1. Plans are generally required to provide this on request, and having the exact language in hand lets your prescriber's office address it point by point rather than guessing at what was missing. It's also worth asking whether the denial letter itself can be re-sent with the specific criteria reference included, since some initial letters are generic. Once you have the document, give a copy to your prescriber's office so their resubmission or appeal can respond to the actual standard rather than a general clinical explanation.

How do these denials typically get overturned?

Medical-necessity denials are commonly reversed at one of two points: either your prescriber resubmits with documentation that directly maps to the criteria you obtained, or the denial goes through a formal appeal. You generally have the right to an internal appeal handled by the plan, and if that's unsuccessful, an external review conducted by an independent party outside the insurance company 13. Because 'not medically necessary' denials often turn on documentation gaps rather than deep clinical disagreement, a well-targeted resubmission resolves a meaningful share of them before an appeal is even needed. For the two escalation routes if a resubmission doesn't work, see what a peer-to-peer review involves and how many chances you get to appeal a prescription denial.

When to loop in your prescriber's office

Since the criteria document is really a checklist for your prescriber's office to answer, the most useful step is bringing it to them directly and asking whether the last submission addressed each point on it. Their office is also the one positioned to request a peer-to-peer conversation with the plan's reviewing physician, which sometimes resolves a medical-necessity dispute faster than a written appeal alone. If the denial involves a specific formulation, like an extended-release version, see what to do when insurance denies the extended-release version for that narrower case. A focused conversation with the exact criteria in hand is usually more productive than a general request to reconsider.

Common questions

No -- this finding reflects a comparison against the plan's own written criteria, not an error by your prescriber or a judgment about their clinical decision. It often means the initial submission didn't include the specific documentation the plan's criteria require, which is a gap that can usually be closed with more targeted information rather than a different treatment plan.

Yes -- asking your plan directly for the specific medical necessity criteria used in your denial is a reasonable, independent step you can take before your prescriber's office resubmits anything. Having the exact document in hand, rather than a general sense of what was missing, makes it easier for their office to target the resubmission precisely.

No, these are distinct findings even though they can appear on similar-looking letters. 'Not medically necessary' means the documentation didn't meet the plan's written standard for that use; 'experimental' or 'off-label' findings are about whether the medication's use for your specific situation is considered established at all, which generally requires a different kind of clinical argument.

Timelines vary by plan, but many have a defined window for reconsidering a denial once new documentation is submitted, often measured in days for standard requests and faster for expedited ones. Asking your plan directly what the timeline is for your specific resubmission, and getting a reference number, helps you follow up without starting the conversation over.

Related

Say it back

How would you explain this to someone you love?

Two or three sentences, just as you’d say it. Gale reflects back what you focused on — a mirror, not a quiz.

If things feel heavy, a person is available anytime — call or text 988.

Talk to a clinician

Gale can help you find a clinician in your state and request a visit.

Find care →

If a denial is affecting your access to care right now

  • —A gap in medication access that's already causing a return of severe symptoms
  • —Thoughts of suicide or of not wanting to be alive while a denial is being sorted out
  • —A mental health crisis that can't wait on an appeal timeline
  • —Confusion about a denial that's leading you to consider going without the medication entirely

Medical necessity criteria and appeal timelines vary by plan and by state; this article describes general patterns, not your specific plan's terms. This is general information, not legal or clinical advice. If you are in crisis, call or text 988 (Suicide & Crisis Lifeline), free and available 24/7.

References

  1. 1.U.S. Centers for Medicare & Medicaid Services / HealthCare.gov (2025). How to Appeal an Insurance Company Decision. HealthCare.gov. link ✓appeal-denied-claiminternal-appealexternal-reviewcoverage-denial
  2. 2.Centers for Medicare & Medicaid Services (CMS) (2025). Other Insurance Protections (including Mental Health Parity). Centers for Medicare & Medicaid Services (CMS). link ✓mental-health-paritymhpaea-parityconsumer-insurance-protections
  3. 3.U.S. Centers for Medicare & Medicaid Services / HealthCare.gov (2025). External Review of a Health Plan Decision. HealthCare.gov. link ✓external-reviewappeal-denied-claimindependent-reviewparity-enforcement

3 sources, numbered by first appearance. General health information, not medical advice. AI-assisted editorial content — every citation independently verified. Editorial policy

← Back to the health library