Getting a continuous glucose monitor depends on your situation: if you have diabetes and use insulin, you’ll need a prescription from your doctor, which most insurers will cover. If you don’t use insulin, you can now buy one model over the counter with no prescription at all. The path you take shapes what you’ll pay and how quickly you can start wearing a sensor.
The Prescription Route
Most CGMs require a prescription. Your primary care doctor, endocrinologist, or other treating provider can write one. There’s no requirement that it come from a specialist. The key is that your provider needs to have seen you for diabetes management within the past six months, either in person or via telehealth, and document that you (or a caregiver) have been trained to use the device.
If you’re already on insulin, the conversation is straightforward. Clinical guidelines recommend CGMs for adults on multiple daily insulin injections or an insulin pump, and also for those on basal insulin alone. Providers are generally familiar with these recommendations and won’t need much convincing. Bring your recent blood sugar logs and your most recent A1C result to the appointment. An A1C of 8.0% or higher strengthens the case, though it’s not the only qualifying factor.
If you have diabetes but don’t take insulin, you can still qualify. Documented episodes of problematic low blood sugar are the alternative pathway. Specifically, insurers look for either two or more episodes where your glucose dropped below 54 mg/dL despite medication adjustments, or a single severe episode where you needed someone else’s help to recover. If you’ve experienced lows like these, make sure your medical records reflect them.
The Over-the-Counter Option
Stelo by Dexcom is the first CGM cleared by the FDA for sale without a prescription. It’s designed for adults 18 and older who are not taking insulin and are not at risk of dangerous low blood sugar. You can order it directly from the manufacturer’s website. This is the simplest path if you’re managing type 2 diabetes with diet and oral medications, or if you’re simply curious about how your body responds to food and exercise. No doctor visit, no insurance paperwork. The tradeoff is that you pay the full retail price yourself.
How Insurance Coverage Works
Private insurance requirements vary widely, not just between companies but between plans within the same company. That said, common documentation requirements include a diabetes diagnosis, evidence that you’re checking fingerstick blood sugar at least three times daily, use of insulin (often three or more daily doses), and an office visit for diabetes management within the past six months. Your doctor typically submits this information as part of a prior authorization request.
One important detail that can save you money and hassle: ask your provider whether your plan covers CGMs under the pharmacy benefit or the durable medical equipment (DME) benefit. The difference is significant. When a CGM is covered under the pharmacy benefit, the process works like filling any other prescription. Your doctor sends the order to the pharmacy, you pick it up, and you pay your normal copay. Some insurers don’t even require prior authorization when CGM supplies are dispensed this way.
When it’s covered under the DME benefit, the requirements tighten considerably. You’ll need detailed documentation of medical necessity, written orders before delivery, and ongoing proof that you’re using the device and still need it. The reimbursement rates for DME suppliers are also lower, which can create delays or limit which suppliers will work with your plan. If your insurer gives you a choice, the pharmacy route is almost always simpler.
Medicare Coverage
Medicare covers CGMs under specific conditions. You must have a diabetes diagnosis, be insulin-treated or have documented problematic hypoglycemia, and your provider must have evaluated your diabetes control within six months before ordering the device. Your provider also needs to confirm that you’ve been adequately trained on the system. Once you’re approved, Medicare requires a follow-up visit every six months to verify you’re still using the CGM and that it remains medically necessary.
What You’ll Pay Without Insurance
Out-of-pocket costs for CGM supplies run roughly $160 to $500 per month, depending on the brand and where you buy. That’s the ongoing cost for sensors and any required transmitters. Every major manufacturer offers some form of financial assistance to bring that number down.
- Abbott (FreeStyle Libre): Offers vouchers for a free 14-day sensor and reader with a $0 copay for eligible patients, letting you try the system before committing.
- Dexcom: Runs a patient assistance program that can reduce pharmacy costs for the G7 by up to 20%.
- Medtronic: Provides discount access options for its MiniMed CGM for people who meet certain criteria.
- Ascensia (Eversense): Offers a financial aid package where eligible users pay as low as $199 per year for its implantable CGM.
Preparing for the Doctor Visit
If you need a prescription, a little preparation makes the process faster. Before your appointment, gather your blood glucose logs from the past few weeks, note any episodes of low blood sugar (especially if you felt confused, shaky, or needed help), and have your most recent A1C result available. If you don’t have recent logs, start checking your fingerstick glucose at least three times a day for a couple of weeks beforehand. Some insurers specifically require this documentation.
Be direct with your provider about why you want a CGM. Good reasons include frequent blood sugar swings your fingerstick checks are missing, difficulty keeping your A1C in range, episodes of low blood sugar you didn’t feel coming, or trouble adjusting insulin doses without real-time data. These align with the clinical criteria insurers use to approve coverage, which makes the authorization process smoother for everyone.
What Happens After You Get One
Once you have your prescription filled or your OTC device delivered, setup is straightforward. You apply a small sensor to the back of your upper arm or your abdomen (depending on the brand), and the device begins a warm-up period before it starts reading your glucose levels. Most sensors require about 60 minutes before they deliver the first reading. After that, the sensor continuously measures your glucose and sends data to your phone or a dedicated reader.
Sensors last between 10 and 15 days before they need to be replaced. You’ll receive a new shipment of sensors on a regular schedule, either from a pharmacy or a DME supplier, depending on how your coverage is set up. If you’re on Medicare or most private plans, expect to check in with your doctor every six months to keep the prescription active and maintain insurance coverage.