You Just Got Denied. Here's What to Do Right Now.
Getting an insurance denial letter for your CGM sensors or diabetes supplies is infuriating β especially when you know how essential this technology is to your daily health. Take a breath. An initial denial is not the end of the road. The majority of appealed insurance denials are overturned, particularly for CGMs, which have strong clinical evidence supporting their necessity. This guide gives you the exact steps, language, and letters you need to fight back β starting today.
Step 1: Read Your Denial Letter Carefully (Within 24 Hours)
Your denial letter must legally include the specific reason for denial. Common denial reasons include:
- "Not medically necessary" β the insurer claims your condition doesn't meet their coverage criteria
- "Step therapy required" β they want you to try a cheaper alternative first
- "Prior authorization not obtained" β your doctor didn't file paperwork before prescribing
- "Non-formulary item" β your specific CGM brand isn't on their approved drug/device list
- "Experimental or investigational" β rare for CGMs, but it happens
Circle the exact denial reason. Your entire appeal strategy depends on it. Also note your appeal deadline β most plans require internal appeals within 180 days of denial under the ACA, but some plans set shorter windows. Do not miss this date.
Step 2: Call Your Insurer Immediately β Use This Script
Call the Member Services number on your insurance card. Ask for the Appeals and Grievances department. When they answer, say:
"Hello, my name is [Name], member ID [XXXXXX]. I received a denial for a Continuous Glucose Monitor on [date]. I'm calling to request the specific clinical criteria used to deny this claim, the name of the reviewing clinician, and instructions for filing a formal internal appeal. I'd also like to request an expedited appeal given the medical urgency of this supply."
Write down every name, date, and reference number. Request that all information be sent to you in writing. Ask specifically: "Does your plan cover CGMs for my diagnosis code?" and "What documentation would reverse this denial?"
Step 3: Gather Your Supporting Documents
A strong appeal is built on documentation. Collect the following before writing your letter:
- Your doctor's Letter of Medical Necessity (LMN) β ask your endocrinologist or PCP to write one specifically addressing the insurer's denial reason
- Your most recent A1C results and blood glucose logs
- Relevant clinical guidelines β the ADA's Standards of Medical Care in Diabetes explicitly recommends CGM for people on insulin and others with hypoglycemia unawareness
- Any peer-reviewed studies showing CGM reduces hospitalizations and improves outcomes (your doctor can provide these)
- Your EOB (Explanation of Benefits) from the denial
Step 4: Send Your Internal Appeal Letter
Send this via certified mail with return receipt and keep a copy of everything.
Sample CGM Insurance Appeal Letter
[Your Name]
[Address]
[Date]
[Insurance Company Name]
Appeals and Grievances Department
[Address from denial letter]
RE: Formal Internal Appeal β Claim Denial for Continuous Glucose Monitor
Member ID: [XXXXXX] | Date of Denial: [DATE] | Reference #: [XXXXXX]
Dear Appeals Review Board,
I am writing to formally appeal the denial of coverage for my Continuous Glucose Monitor (CGM) system, denied on [DATE] under reason code [CODE/REASON FROM LETTER]. I believe this denial is inconsistent with my plan's coverage provisions, established clinical guidelines, and my documented medical need.
I have been diagnosed with [Type 1 / Type 2 Diabetes], and I am currently managed with [insulin / basal-bolus therapy / insulin pump]. My most recent A1C is [X%], and I have experienced [hypoglycemic episodes / difficulty maintaining glycemic control] that place me at serious medical risk without continuous glucose monitoring.
The American Diabetes Association's Standards of Medical Care in Diabetes (2024) recommends CGM as standard of care for individuals on insulin therapy and those experiencing hypoglycemia unawareness β both of which apply to my case. Enclosed is a Letter of Medical Necessity from my treating physician, [Dr. Name], MD, supporting this appeal.
I respectfully request that a physician reviewer in the specialty of endocrinology conduct this appeal review, per my rights under ERISA / ACA regulations.
If this internal appeal is not resolved in my favor within [30 days for standard / 72 hours for expedited], I will pursue an external independent review and file a complaint with [my state insurance commissioner / CMS if Medicare].
Enclosed: Letter of Medical Necessity, A1C records, blood glucose logs, ADA clinical guidelines excerpt, EOB
Sincerely,
[Your Name]
[Phone Number] | [Email]
Step 5: If Internal Appeal Fails β Go External
If your internal appeal is denied, you have the right to an External Independent Review under the ACA. This is conducted by an independent organization β not your insurer β and their decision is legally binding. File your external appeal request with:
- Private insurance: Your state's Department of Insurance (find your commissioner at naic.org)
- Medicare: File a redetermination request with CMS at medicare.gov, then escalate to a Qualified Independent Contractor (QIC) if needed
- ERISA employer plans: File with the U.S. Department of Labor at dol.gov
External appeals are free to file and overturn internal denials at surprisingly high rates for CGM cases.
Don't Go Without Supplies While You Fight
Insurance battles can take weeks. You cannot afford to go without your CGM sensors or diabetes supplies during that time. MDS Diabetes (mdsdiabetes.com) carries a full range of FSA/HSA-eligible CGM supplies and diabetes management products β no prior authorization required. You can purchase directly and submit for FSA/HSA reimbursement immediately, keeping your care continuous while your appeal moves forward.
Fighting an insurance denial is stressful, but you have real rights and real recourse. Use this guide, get your doctor on your side, and don't stop at the first no.