Last reviewed August 21, 2026 by the Medically Modern coverage team. Device specifications come from Dexcom’s US product documentation and the published clinical studies cited at the end of this page.
The Dexcom G7® is a continuous glucose monitor, usually shortened to CGM. Instead of pricking your finger to get one glucose number at one moment, you wear a sensor that measures glucose continuously and sends a new reading to your phone every five minutes. Over a day that is roughly 288 readings instead of four or five.
That change — from isolated numbers to a continuous line — is the whole point. A fingerstick tells you where you are. A CGM tells you where you are, which direction you are heading, and how fast.
The short version: a prescription glucose sensor for people with any type of diabetes, ages 2 and up. Worn 10 days (or 15 with the newer sensor). Reads every 5 minutes. No fingersticks needed to get a reading. Alerts you before a serious low. Works with several insulin pumps.
What it measures, and why that matters
The G7 does not measure blood glucose directly. It measures glucose in interstitial fluid, the fluid sitting between the cells just under your skin. A tiny filament, inserted a few millimeters under the surface, does the sensing.
Interstitial glucose tracks blood glucose closely but not instantly. When your glucose is changing quickly — after a meal, during exercise, while a correction dose is landing — the sensor reading can lag behind a fingerstick by several minutes. This is normal physiology, not a defect, and it explains most of the moments where a sensor and a meter disagree. We cover that in detail on the accuracy page.
What arrives, and what you need
Compared with the Dexcom G6, the G7 collapsed two pieces of hardware into one. The G6 used a sensor plus a separate reusable transmitter that you clipped in and moved between sensors. The G7 sensor has the transmitter built in, and the whole thing is discarded together at the end of a wear.
So there are really three pieces:
- The sensor. A single disposable unit, about 60% smaller than the G6 sensor, applied with a one-press applicator. This is the only part you wear. The sensor page covers insertion, wear sites, and what to do when one fails early.
- The Dexcom G7 app. Runs on most current iPhones and Android phones and is where your readings, graphs, and alerts live. Dexcom publishes a compatibility list — check your specific model before you order, because it is the most common unpleasant surprise.
- A receiver, optionally. A small dedicated display device for people who would rather not use a phone, or whose phone is not compatible. Worth knowing: the receiver is not waterproof, even though the sensor is.
You also need a prescription. The G7 is a prescription device in the US.
Do not confuse the G7 with Stelo. Dexcom also sells Stelo, an over-the-counter sensor you can buy without a prescription. It is a different product for people who do not use insulin, and it is not indicated for anyone with a history of severe lows. If you use insulin, Stelo is not the product you are looking for.
Who it is cleared for
The FDA cleared the G7 in December 2022 for people with all types of diabetes — type 1, type 2, and gestational — from age 2 upward. That is a broader indication than many people assume; the G7 is not a type 1 device.
Approved wear sites depend on age. The back of the upper arm is approved from age 2 up. The upper buttocks is approved for children aged 2 to 6. The abdomen is approved for adults.
The newer Dexcom G7 15 Day sensor is cleared only for adults 18 and older. If you are buying for a child, the standard G7 is the one that applies. The two models differ in more than wear time, and we compare them on the G7 15 Day vs G7 page.
Being cleared for a device and being covered for one are different questions. Medicare, for instance, applies its own criteria on top of the FDA indication, and those criteria are narrower. Our eligibility page walks through what payers actually require.
How the day-to-day works
You apply a sensor, wait out a warm-up, and then readings appear on their own until the sensor expires.
| Dexcom G7 | Dexcom G7 15 Day | |
|---|---|---|
| Wear time | Up to 10 days, plus a 12-hour grace period | Up to 15 days, plus a 12-hour grace period |
| Warm-up | 30 minutes | 60 minutes |
| Reading interval | Every 5 minutes | Every 5 minutes |
| Ages | 2 and older | 18 and older |
| Calibration | None required | None required |
That 12-hour grace period is more useful than it sounds. It means a sensor ending at 3am does not have to be replaced at 3am.
The G7’s 30-minute warm-up was a real improvement over the G6, which took two hours. The 15 Day sensor moved back up to 60 minutes because it runs a different algorithm to support the longer wear.
Alerts, which are the part people underuse
Most alerts on the G7 are yours to configure — high and low thresholds, rate-of-change warnings, quiet hours. Two are worth knowing about specifically:
- Urgent Low fires at 55 mg/dL. It is fixed there and cannot be changed or switched off; the FDA requires it.
- Urgent Low Soon fires when the system predicts you will reach 55 mg/dL or below within 20 minutes. This is the one people forget to turn on, and it is the difference between treating a low and catching one before it arrives.
Through Dexcom Follow, readings can be shared with up to 10 followers — a partner, a parent, a school nurse. For a child with type 1, this is often the feature that changes a family’s nights.
Wondering what it would cost you?
We verify your benefits with your insurer and tell you your actual monthly number before you commit to anything.
What it connects to
The G7 is cleared as an iCGM, short for integrated CGM. The practical meaning of that designation is that it is permitted to drive other devices rather than just display numbers.
In the US it currently works with the Tandem t:slim X2, Tandem Mobi, Omnipod 5, and Beta Bionics iLet. In those systems the pump reads the sensor and adjusts insulin delivery automatically between meals and overnight.
Pump compatibility is specific to model and software version, and support for the 15 Day sensor arrived later than support for the standard G7. Confirm with your pump manufacturer before switching sensors, not after.
What it will not do
Worth being straight about, because the marketing rarely is:
- It does not eliminate fingersticks entirely. No routine calibration is needed, but Dexcom directs you to confirm with a meter before treating when your symptoms and the reading disagree. Keep a meter and strips.
- It does not dose insulin by itself. Unless it is paired with an automated insulin delivery system, it reports and alerts. Nothing more.
- It is not equally accurate all the time. Accuracy drops when the sensor is compressed, and certain medications interfere. The accuracy page covers both.
- Sensors sometimes fail early. In the 15 Day clearance study, 73.9% of sensors lasted the full 15 days — meaning roughly one in four did not. Dexcom replaces sensors that fail prematurely, but you have to call and report it.
- It will not fix a treatment plan on its own. A CGM shows you what is happening. What to change is a conversation with your doctor or diabetes educator.
Getting one, and what it costs
Two things have to happen: a prescription from your clinician, and a decision about how it gets billed. The second is where most of the money is won or lost, because the same sensors can cost wildly different amounts through a pharmacy benefit versus a medical benefit.
Dexcom reports that most people with CGM coverage pay $20 or less per month. That is Dexcom’s own figure and it applies to people who are covered. Without coverage, retail runs closer to $500–$575 a month, which is why the billing route matters so much.
The full picture is on the insurance page, the Medicare page, and the cash-price page. Or skip the reading: tell us your plan and we will verify it and tell you the number.
Frequently asked questions
Is the Dexcom G7 waterproof?
The sensor is. Dexcom states it may be submerged to about 8 feet of water for up to 24 hours when properly applied, so showering and swimming are fine. The optional receiver is not waterproof and should be kept dry.
Does the Dexcom G7 hurt to put on?
Most people describe it as a brief pinch or nothing at all. The applicator inserts a thin flexible filament, not a needle that stays in. Discomfort that persists past insertion is not typical and is worth reporting to Dexcom, since it can indicate a bad sensor.
Can you use the Dexcom G7 if you are not on insulin?
Yes — the FDA clearance covers all types of diabetes regardless of treatment. Insurance is a separate matter, and many plans cover CGMs more readily for people using insulin. Dexcom reports about 87% of insulin users are covered versus about 50% of those not using insulin. Both figures are Dexcom’s.
What is the difference between the Dexcom G7 and the G6?
The G7 sensor is about 60% smaller, has the transmitter built in rather than as a separate reusable piece, warms up in 30 minutes instead of two hours, and adds the Urgent Low Soon alert. Both are worn 10 days.
Can you get a Dexcom G7 without a prescription?
No. The G7 requires a prescription in the US. Dexcom’s Stelo is sold over the counter, but it is a different sensor intended for people not using insulin and is not indicated for people with problematic hypoglycemia.
Sources: Dexcom G7 overview, Dexcom sensor wear time, Dexcom G7 15 Day warm-up, Dexcom Urgent Low Soon alert, Dexcom pump compatibility, Dexcom G7 FDA clearance, Garg et al., accuracy of the 15.5-day G7 iCGM (PubMed), FDA on over-the-counter CGMs.