INSURANCE

How do I appeal a denied insurance claim?

SHORT ANSWER

Read the denial letter for the exact reason and deadline, request your full claim file and the policy language used, then file a written appeal that answers the specific reason — ideally with a letter of medical necessity from your doctor. A large share of appealed denials are overturned, so it’s worth doing.

A denied insurance claim is often reversible — studies of health-plan appeals consistently find a large share are overturned, yet most people never appeal. The key is to answer the exact reason for denial, which the insurer must state in writing. Common reasons each have a specific counter: "not medically necessary" is met with a letter of medical necessity from your treating physician; "out-of-network" may be challenged if no in-network option was available; "experimental" can be rebutted with clinical evidence; a coding or paperwork error is often fixed with a corrected submission. Request your full claim file and the specific policy provisions and medical criteria the insurer applied — you have the right to them, and they frequently reveal the denial was procedural. Then file your appeal in writing before the deadline (often 180 days), keep proof, and if the internal appeal fails, escalate to an independent external review.

What to do, in order

  1. Read the denial letter for the exact reason and the appeal deadline.
  2. Request your full claim file, the policy language, and the medical criteria used.
  3. Match your appeal to the specific denial reason cited.
  4. Get a letter of medical necessity from your doctor if relevant.
  5. File the written appeal before the deadline; keep proof of submission.
  6. If the internal appeal fails, request an independent external review.

Common questions

Are insurance appeals worth it?

Often yes. Reviews of denied health claims routinely find a substantial share are overturned on appeal — yet most people never file one, so appealing meaningfully improves your odds.

What’s the most powerful thing to include?

For a "not medically necessary" denial, a detailed letter of medical necessity from your treating physician is usually the strongest single element of an appeal.

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This is general information, not legal, tax, or financial advice, and it doesn’t create a professional relationship. Rules have exceptions and change over time. For advice on your specific situation, consult a licensed professional.