Getting a Dexcom continuous glucose monitor (CGM) requires a prescription from a healthcare provider, but the exact path depends on your insurance, your diabetes type, and how you plan to pay. Most people with diabetes who use insulin or experience low blood sugar episodes can qualify. Here’s how the process works from start to finish.
Who Qualifies for a Dexcom CGM
Dexcom CGMs are FDA-cleared for people with diabetes, including Type 1, Type 2, and gestational diabetes. You don’t need to be on an insulin pump or have a specific A1C level. Common reasons a provider will prescribe one include taking multiple daily insulin injections, using an insulin pump, experiencing frequent low blood sugar, having hypoglycemia unawareness (where your blood sugar drops without you feeling it), wide swings in glucose throughout the day, or simply not hitting your glucose targets with your current approach.
If you’re on Medicare, coverage expanded in 2023 to include all patients with diabetes who are treated with insulin or who have a history of hypoglycemia. You (or a caregiver) also need to have received enough training to use the device properly, which your prescribing provider confirms by writing the prescription. Medicaid coverage varies more: as of 2023, 45 states and Washington, D.C. offer some level of CGM coverage, but the specific rules differ significantly from state to state.
Getting the Prescription
Start with the provider who manages your diabetes. This could be an endocrinologist, a primary care doctor, or a nurse practitioner. Tell them you’re interested in a CGM and ask specifically about Dexcom. They’ll evaluate whether you meet the clinical criteria and, if so, write a prescription.
For Medicare patients, the provider also needs to complete a Certificate of Medical Necessity, which serves as both the prescription and the documentation Medicare requires for reimbursement. They’ll include chart notes showing you meet coverage criteria, and you’ll need to provide images of your insurance cards (front and back). Private insurers often require prior authorization, which your provider’s office typically handles by submitting clinical documentation showing why a CGM is medically necessary for you.
If your current provider seems unfamiliar with CGMs or resistant to prescribing one, an endocrinologist is your best bet. Diabetes specialists prescribe these devices routinely and know how to navigate the paperwork.
How Insurance Coverage Works
How your insurance covers a Dexcom CGM falls into one of four categories, and the distinction matters for your wallet. Your CGM supplies might be covered only under durable medical equipment (DME) benefits, only under pharmacy benefits, under pharmacy for the CGM but DME for pump supplies, or under both DME and pharmacy benefits where you get to choose.
If you have the option to go through either benefit, compare costs before deciding. Insurance companies often set different copay percentages for each. For example, your plan might charge 20% of the cost through DME but only 10% through pharmacy benefits. Call your insurance company and ask two straightforward questions: “What is my out-of-pocket cost for a Dexcom G7 under DME benefits?” and “What is my out-of-pocket cost for a Dexcom G7 under pharmacy benefits?” The answer could save you hundreds of dollars a year.
When your CGM goes through pharmacy benefits, you pick it up at a retail or mail-order pharmacy, just like a regular prescription. When it goes through DME benefits, it ships from a medical supply company. Authorized Dexcom distributors for Medicare patients include Byram Healthcare, CCS Medical, Solara Medical Supplies, Edgepark Medical Supplies, and Advanced Diabetes Supply. For pharmacy fulfillment, Dexcom supplies are distributed through Cardinal Health, McKesson, and Cencora, which stock major retail pharmacies.
Paying Without Insurance
Without insurance coverage, the retail cash price for Dexcom G7 sensors runs several hundred dollars per month. Dexcom offers a Pharmacy Savings program that knocks over $200 per month off the retail price of a monthly sensor pack, plus $240 off a receiver over a one-year period. You still need a prescription to use this program, but it significantly reduces the out-of-pocket burden.
Dexcom also runs a patient assistance program for people who can’t afford the device. Additionally, Dexcom offers a voucher program where new patients can get a free CGM product, redeemable with a prescription at a pharmacy. Ask your provider about this option if you want to try the system before committing financially.
Choosing Between the G7 and Older Models
The Dexcom G7 is the current-generation device and what most new users will be prescribed. Compared to the G6, it’s 60% smaller on your body, combining the transmitter and sensor into a single unit you apply with one click. The G6 required a separate transmitter that clipped onto the sensor.
Practical differences that matter day to day: the G7 warms up in 30 minutes compared to 2 hours for the G6, so you’re getting readings much faster after inserting a new sensor. Both last 10 days, but the G7 adds a 12-hour grace period after the sensor expires, giving you time to transition to a new one without a gap in data. Accuracy is slightly better on the G7 (8.2% average error versus 9% on the G6).
The G7 is worn on the back of the upper arm for anyone age 2 and older. It is not approved for wear on the abdomen, which was an option with the G6. The redesigned app integrates Dexcom’s Clarity reporting software directly, so you can see food, insulin, and activity events on your trend graph without switching between apps. Alert customization is also more flexible: you can set rise and fall thresholds, create two different alert profiles, silence all alerts for up to 6 hours, and snooze alarms in increments from 15 minutes to 6 hours.
The Typical Timeline
From your first appointment to wearing a sensor, the process usually takes one to four weeks. The appointment itself is straightforward: your provider writes the prescription and, if needed, submits prior authorization to your insurer. Insurance approval can take a few days to a couple of weeks. Once approved, the prescription goes to a pharmacy or DME supplier, and you either pick it up or wait for it to ship.
If prior authorization is denied, your provider can appeal. Common reasons for denial include missing documentation or the insurer classifying you as not meeting their specific criteria. Your provider’s office can usually resolve this by resubmitting with additional chart notes. If your private insurance doesn’t cover CGMs at all, the cash-pay and savings program routes described above are your alternatives.