Insurance Denied Your CGM? How to Write a Winning Appeal Letter (Free Tool)

Insurance & Advocacy · 5 · February 16, 2026

Your endocrinologist prescribed a continuous glucose monitor. Your insurance company said no. "Not medically necessary." Three words that ignore your HbA1c of 8.2%, your three hypoglycemic episodes last month, and the DIAMOND trial showing CGMs reduce HbA1c by 0.6% in exactly your patient profile.

Here is what the insurance company is counting on: that you will accept the denial. Sixty percent of patients do. They feel defeated, confused by the appeals process, or simply too exhausted to fight. This is by design. Every denial that goes uncontested saves the insurer money.

The Math Favours Appealing

Patients who appeal with proper clinical documentation and legal references overturn denials more than 50% of the time. For CGM specifically, the overturn rate is even higher because the clinical evidence is overwhelming. The DIAMOND trial data alone — 0.6% HbA1c reduction, published in JAMA — demolishes most "not medically necessary" denials.

What a Winning Appeal Contains

A generic letter saying "I need this device" will be denied again. A winning appeal contains:

Medical necessity argument citing peer-reviewed evidence specific to your condition and the denied device. Relevant specialty society guidelines — ADA Standards of Care 2026 explicitly recommend CGM for all patients on intensive insulin therapy. Cost-effectiveness analysis showing that CGM prevents hypoglycemic emergencies that cost $17,000–$25,000 per ER visit. Legal references — ERISA Section 502(a)(1)(B) gives you the right to sue for wrongful benefit denial; the ACA External Review provisions require independent medical review on appeal.

Writing this letter takes a health policy lawyer 2–3 hours and costs $500–$1,000. Or you can use Journey for Health's Prior Authorization Agent.

How the Agent Works

Enter the procedure name, CPT code, your ICD-10 diagnosis codes (added as chips — E11.65 for Type 2 with complications, for example), the insurance payer name, the denial reason, and a clinical summary of your situation. The platform generates a multi-page appeal letter with cited clinical guidelines, legal references, and a strength score from 1–10.

A score below 6 means you should gather more documentation before submitting. A score above 7 means the letter has strong evidence and legal foundation. You can copy the letter to clipboard or download it as a text file, ready to mail or email to your insurer.

The legal references are real: ERISA Section 502, state-specific mandates (California AB 72, Texas SB 1264), ACA External Review provisions. The clinical citations are real: DIAMOND trial, STAR 3, STAMPEDE, ADA Standards of Care. This is not a template with your name pasted in. It is a legally referenced document built from your specific clinical situation.

Generate your appeal at Prior Authorization Agent.