Not medically necessary: how to appeal

The insurer agrees the service exists in your plan but says your specific case does not meet their clinical criteria. Letter of medical necessity from the treating physician citing the plan's own medical policy.

Why this denial happens

  • The chart did not include the diagnosis codes the policy requires
  • Severity was not quantified
  • Conservative therapy was not documented
  • The reviewer applied the wrong medical policy

What overturns it

  • Letter of medical necessity from the treating physician citing the plan's own medical policy
  • Severity scores, imaging, or labs that meet the criteria
  • Documented failure of required prior therapy

Evidence checklist

  • Treating physician letter
  • Office notes from the last 12 months
  • Imaging or lab reports
  • Prior treatment history
  • Specialty guideline citation

Medical necessity denials are the most common and the most overturnable when the appeal cites the insurer's own clinical policy bulletin.

Draft an appeal for a "Medical necessity" denial

Free analysis identifies the cited policy and missing evidence. Then a finished letter.

Draft my appeal letter

FAQ

What does "Not medically necessary" mean on a denial letter?+

The insurer agrees the service exists in your plan but says your specific case does not meet their clinical criteria.

How long do I have to appeal?+

180 days from the date of denial for ERISA group plans and ACA marketplace plans. 60 days for Medicare Advantage. Check the denial letter for your specific deadline.

What is the success rate for this kind of appeal?+

Outcomes vary, but medical-necessity and step-therapy appeals overturn at meaningful rates when the appeal cites the insurer's own policy and the chart documents the required criteria.

Other denial reasons

Not legal or medical advice. This page is a self-help resource. You make your own decisions. Strip personal identifiers (name, date of birth, address, member ID) from any document before uploading or sharing. The information here summarizes commonly-published payer policies and federal rules; confirm against your specific plan document and the current denial letter before acting.