Not legal advice - Denial Decoder helps you understand insurance denials; it doesn't replace a licensed attorney, doctor, or patient advocate.

Denial Decoder
For patients, by patients

Your insurance denial, decoded.

Paste your denial letter or upload a photo. In about thirty seconds you'll get a plain-English explanation, your appeal deadline, the exact escalation steps, and a list of documents to gather.

  • No account required
  • We don't store your letter on our servers
  • PPO • HMO • Medicare • Marketplace
≈80%of appeals that get filed are overturned
<1%of denied claims are ever appealed
30 secto understand your letter

Source: Kaiser Family Foundation analysis of ACA marketplace claims.

See a real denial, decoded

From confusing letter to clear next step - in about 30 seconds.

The letter you got
Denied

NORTHSHORE HEALTH PLAN - ADVERSE DETERMINATION

Claim #2026074155001 · CPT 70551

DETERMINATION: DENIED (MN-02).

Services not deemed medically necessary per plan medical policy; conservative treatment not documented prior to advanced imaging.

You may request internal appeal within 180 days.

What Denial Decoder gives you
Medical necessity

Here's what it actually means

They denied your MRI because they want proof you tried 6 weeks of conservative treatment first.

Appeal by Sep 10, 2026

Next step: Ask your doctor for a Letter of Medical Necessity, then file your internal appeal.

Plain-English readDeadlineEscalation stepsDocuments to gather

Real example, simplified. We don't store your letter on our servers, and it's never used to train AI.

How it works

Denial letters are written by underwriters, for underwriters. We translate them into something you can actually act on.

  1. Step 1 - Paste or upload your letter

    Add the text or a photo / PDF. PPO, HMO, Medicare, Medicaid, and ACA supported.

  2. Step 2 - We decode it in ~30 seconds

    We pull out the real denial reason, your deadline, and the plan rules that apply.

  3. Step 3 - You take action

    Follow the escalation steps, gather the listed documents, and generate your appeal letter.

For patients, by patients

Built from a letter we almost gave up on

Denial Decoder started with a letter my father got - a denial none of us could understand, with a deadline we almost missed. We learned the hard way that most denials can be appealed, and that most people never do. So we built the tool we wish we'd had: paste your letter, get it in plain English, and know exactly how to fight back. For patients, by patients.

Built around your privacy

We don't store your letter on our servers, and it's never used to train AI. To analyze it, it's sent to our AI provider (Google Gemini) under an agreement that doesn't use your data for training. As with any online service, transient processing by our infrastructure providers may briefly occur.

  • No accounts, no profiles, no tracking pixels in your letter.
  • AI explanations are sourced from a curated knowledge base, not the open web.
What you get
  • Plain-English read of the denial reason
  • Your appeal deadline & how to count the days
  • Step-by-step escalation ladder
  • Checklist of documents to gather
  • Optional: formatted appeal letter PDF
Start decoding
Free templates

Rather not upload anything? Use our free templates.

You don't have to share your letter to get help. Download ready-to-edit appeal templates and fill them in yourself - completely offline, nothing sent to us.

Appeal letter template

A formatted health-insurance appeal letter you can customize with your own details.

Letter of Medical Necessity template

For your doctor to complete, the strongest attachment for medical-necessity and prior-authorization denials.

Want it done for you instead? Decode your letter.