Getting insurance to cover a continuous glucose monitor (CGM) comes down to meeting specific medical criteria, making sure your doctor submits the right documentation, and knowing which benefit channel to use. Most plans, including Medicare, will cover a CGM if you can demonstrate medical necessity, but the paperwork and approval process trips up a lot of people. Here’s how to navigate it.
What Insurance Companies Require for Approval
Whether you have Medicare, Medicaid, or private insurance, the core eligibility criteria are similar. You need a diabetes diagnosis, and you need to meet at least one of these conditions: you use insulin, or you have a documented history of problematic low blood sugar episodes. For the low blood sugar route, insurers typically want to see either more than one episode where your glucose dropped below 54 mg/dL despite attempts to adjust your treatment plan, or a single severe episode where you needed someone else’s help to recover.
Your doctor also needs to confirm that you (or a caregiver) have been trained to use the specific CGM being prescribed, and the device must be prescribed in line with its FDA-approved use. These aren’t just checkbox formalities. If any of these elements are missing from your paperwork, the claim can be denied on a technicality.
There’s one timing requirement that catches people off guard: your doctor must have had an in-person or telehealth visit with you within six months before ordering the CGM, specifically to evaluate your diabetes management. If you haven’t seen your doctor recently, schedule that visit first. After you start using a CGM, you’ll also need a follow-up visit every six months to keep your coverage active. These visits document that you’re actually using the device and sticking with your treatment plan.
The Documentation Your Doctor Needs to Submit
The most common reason for denial isn’t that you don’t qualify. It’s incomplete paperwork. Your doctor’s office needs to provide a clear trail of evidence that includes your diabetes diagnosis with the correct billing codes, a prescription for the specific CGM device, and proof that you meet the insulin or hypoglycemia criteria. If you’re qualifying through low blood sugar events, your medical records should include glucose logs, lab results, or clinical notes showing those episodes happened and that your treatment plan was already adjusted at least once before the CGM was requested.
Before your appointment, ask your doctor’s office if they’ve submitted CGM prior authorizations before and whether they have the insurer’s specific form. Some insurers use a simplified one-page attestation form, while others require detailed chart notes. Knowing which format your plan expects saves weeks of back-and-forth.
Pharmacy Benefit vs. Medical Equipment Benefit
This is one of the most overlooked ways to simplify the approval process. CGMs can be covered under two different parts of your insurance: the durable medical equipment (DME) benefit or the pharmacy benefit. The path you choose changes everything about how easy it is to get approved and how much you pay out of pocket.
Under the DME benefit, suppliers face strict medical necessity checks. Your provider has to supply chart notes, glucose logs, written orders, and ongoing documentation. The process is slow and paperwork-heavy. Under the pharmacy benefit, the process often works like filling any other prescription: your doctor sends an order to the pharmacy, you pick up your CGM sensors with a normal copay. Some insurers don’t even require prior authorization for CGMs dispensed through a network pharmacy under the drug benefit.
Ask your insurance company whether your plan covers CGMs under the pharmacy benefit. If it does, have your doctor send the prescription to your pharmacy instead of ordering through a DME supplier. This single switch can eliminate most of the documentation headaches and get sensors in your hands faster.
If You Don’t Use Insulin
Coverage gets harder if you manage your Type 2 diabetes without insulin. The American Diabetes Association and the American Association of Clinical Endocrinology both now endorse CGM use for people on less-intensive therapy, including oral medications alone. But insurance coverage hasn’t caught up. Many plans still limit or deny CGM coverage for people who aren’t on insulin.
If you’re in this situation, your best options are to document problematic hypoglycemia episodes if they’ve occurred, ask your doctor to write a detailed letter of medical necessity explaining why a CGM would improve your specific situation, or explore whether your plan has any exceptions process. Some plans will approve coverage if your A1C is above a certain threshold or if you’ve had difficulty managing your blood sugar with standard fingerstick monitoring.
What to Do When Your Claim Is Denied
A denial is not the final answer. Insurance appeals overturn denials regularly, especially when the original submission was missing documentation. The process has three levels, and you should be prepared to use all of them.
The first-level appeal is a request for your insurance company to reconsider. You or your doctor contact the insurer, and your doctor can request a “peer-to-peer review,” which means speaking directly with the insurance company’s medical reviewer to make the case. This is often the most effective step because it lets your doctor explain the clinical situation in a way that paperwork alone can’t convey. Have your insurance plan number, member number, claim number, and the date of service ready before calling.
If the first appeal fails, a second-level appeal goes to a medical director at your insurance company who wasn’t involved in the original decision. You’ll want to include any additional documentation: updated glucose logs, a formal letter of medical necessity from your doctor, or evidence that your condition has worsened.
The third option is an independent external review. An outside reviewer and a physician in the same specialty as your doctor evaluate your case independently. This is your strongest tool if internal appeals haven’t worked, and insurers are required by law to offer it.
Before you start the appeals process, call member services and ask exactly why the claim was denied. The explanation of benefits (EOB) document will list a reason code, but a phone call often reveals the specific missing piece, whether that’s a diagnosis code, a recent office visit, or a particular form.
Manufacturer Programs That Lower Your Cost
Even with insurance approval, copays for CGM sensors add up. Manufacturer assistance programs can close the gap.
- Abbott (Libre 2, Libre 3): People with commercial insurance can get two sensors for $75 and a reader for $65. A separate program provides one free sensor and reader to new users. These discounts are not available to people on Medicare.
- Dexcom (G7): Offers a patient assistance program for people with Type 1 diabetes who aren’t on a government plan and whose income is below 400% of the federal poverty level. A $200 savings coupon is available for people with commercial insurance or no insurance. Dexcom also partners with Amazon Pharmacy and GoodRx for reduced pricing.
- Medtronic (Guardian sensors): For people without sensor coverage, including those on Medicare, the cost drops to $60 per box of five sensors (each lasts seven days) and $180 per transmitter. If you’ve recently lost your job or health insurance, Medtronic provides up to three months of sensors at no cost.
Traditional Meters as a Backup
If CGM coverage isn’t available to you right now, standard blood glucose meters and test strips are covered more broadly. Medicare Part B covers up to 300 test strips and 300 lancets every three months for people who use insulin, and 100 of each for people who don’t. If your doctor documents that you need to test more frequently than those limits allow, Medicare can approve additional supplies, though you may need to keep a log showing your actual testing frequency to justify the increase. Most private insurers follow similar guidelines for fingerstick supplies, often with lower out-of-pocket costs than CGMs.