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Dexcom FAQ

Dexcom FAQ

Find answers to some of the most frequently asked questions about the Dexcom G6, a popular continuous glucose monitoring (CGM) system used by people with diabetes. Whether you're a new user or a long-time customer, this page is designed to provide you with the information you need to make the most of your device. From setting up your system to interpreting your data, we've got you covered.

Can I go through airport security with my Dexcom G6?

Yes, but make sure not to go through the body scanners. You can go through metal detectors, be hand-wanded and even keep your receiver on during your flight.

Can I restart the Dexcom sensor after 10 days?

No. Dexcom sensors are designed to last for a maximum of 10 days, after which time you will be required to insert a new sensor.

Image of the Dexcom Replace Sensor Alert.

Can I share my data with my providers?

Yes, and Performance Home Medical will also send you an invitation to register for Dexcom Clarity. If you already have an existing Dexcom Clarity account, you will not need to create a new one and just need to accept the invite.

To download the app open your app store and search for Dexcom Clarity, or

  • Android users, click here.
  • iPhone users, click here.

Can I share my Dexcom G6 glucose data with followers?

Up to 10 designated persons (followers) can download the Dexcom Follow app and will be able to remotely monitor your glucose data.

Click here to download the Dexcom Follow app.

Do I need to use my Dexcom receiver for my CGM System to work?

You have the flexibility to use only the Dexcom G6 app, only the Dexcom receiver, or both at the same time.

For Medicare customers: Medicare does not cover Dexcom G6 CGM supplies that are used only with a smartphone or other mobile device. Medicare criteria also apply. Some examples of how a Medicare patient may use a smart device with their Dexcom receiver:

  1. Uses both the receiver and a smartphone throughout the day.
  2. Uses the receiver some days of the week and their smartphone other days of the week.

Does the Dexcom G6 CGM System require calibrations?

No. If you entered the unique G6 sensor code during setup, there’s no need to calibrate.

How accurate is the Continuous Glucose Monitoring (CGM) system?

The sensors will not always show the same value as a finger stick as it is measuring the interstitial glucose rather than the blood glucose. But the two values are typically within 9% of each other:

Dexcom vs. Abbott FreeStyle Libre: CGM Function, Accuracy, and Cost (

How does the Urgent Low Soon alert work and how is it different from the Fall Rate?

The Urgent Low Soon alert can warn users in advance of a severe hypoglycemic event. The alert will notify you within 20 minutes of a reading of 55 mg/dL or lower. This notification gives you time to take appropriate action before a low event occurs.

The Fall Rate notifies you when your glucose level is falling 2 or 3 mg/dL each minute.

How long should my Dexcom sensor last? What if it doesn’t seem accurate or falls off?

Your sensor should last for 10 days.

Contact Dexcom Support Team if your sensor falls off early at 1-844-607-8398, 24 hours a day; 7 days a week.

To improve your call experience please have the following available upon calling:

  • Dexcom transmitter serial number, and
  • Dexcom Sensor LOT number, and
  • Dates of insertion for sensors, and/or
  • Dates of activation for transmitters.

How long should my Dexcom transmitter last?

The transmitter battery is good for 3 months.

  • Starting at 3 weeks before the end of its battery life, you will get warnings that count down the transmitter battery life until you have 10 days remaining.
  • If you haven’t received your final 10-day transmitter battery life warning, you can reuse the transmitter for your next sensor session.
  • If the transmitter battery has less than 10 days remaining, you won’t be able to start a new sensor session and will see “Pair New Transmitter.”

Should my CGM and fingerstick have similar values even though they measure different things?

Yes, for glucose values less than 100 mg/dL, the CGM value should be within 15 mg/dL of the blood glucose meter number. For glucose values greater than 100 mg/dL, the CGM value should be within 15% of the meter value.

What can I do to help my CGM stay on for 10 days?

After following the manufacturer's guidelines and inserting your sensor, we recommend:

  • Trying medical grade bandages/tapes or waterproof adhesive overlay patches.
  • Medical-grade bandages/tape can be applied.
  • Do not remove bandages/tape once applied until the sensor is ready for removal.
  • If your skin has higher oil/moisture content, consider putting on the over-patch or medical tape immediately after inserting the sensor.
  • Add extra adhesive, such as SkinTac. Put the additional adhesive under the patch (on your skin), avoiding the spot where the needle inserts. Make sure to let dry before attaching the sensor.
  • Dexcom will also allow customers one pack of adhesives 10, every 30 days, per address.

What do I do if I receive the Sensor Failed alert?

Your inserted sensor will no longer give CGM values, remove the failed sensor. Insert a new sensor and contact Dexcom’s Technical Support 24/7 at 1-844-607-8398.

What do I do if my Dexcom G6 sensor fails during the warmup period?

You should first ensure that your sensor was correctly inserted:

  1. Make sure the previous sensor session ended or if the system still trying to connect with a previous sensor.
  2. Make sure the transmitter’s serial number is correctly entered into the receiver or smart device.
  3. Make sure the transmitter is not beyond the 90-day activation period.
  4. Make sure the transmitter is snapped in correctly and the tab is seated under the plastic lip in the slot.
  5. Make sure the sensor site isn’t bleeding when inserted.

Wait up to 3 hours while the system fixes itself. If not corrected after 3 hours, you’ll see “Sensor Failed”. Contact Dexcom’s Technical Support 24/7 at 1-844-607-8398.

What do I do if the Dexcom G6 wire breaks off?

Don’t ignore broken or detached sensor wires. A sensor wire could remain under your skin. If this happens, please contact Dexcom’s Technical Support 24/7 at 1-844-607-8398.

What do the Glucose Trend Arrows mean?

It indicates the direction your glucose is going:

Illustration showing Dexcom glucose trend arrows with short explanation next to each.

What happens if I have trouble starting my Dexcom G6 sensor session?

Ensure that your Dexcom G6 transmitter is paired correctly and that your previous sensor session has ended.

What if I lost my Dexcom sensor code?

Without your sensor code, you’ll need to calibrate twice after your 2-hour sensor warmup is complete, a third time 12 hours later, a fourth time 12 hours after that, and then once every 24 hours.

What is a sensor code and why do I need one?

A sensor code allows you to use the Dexcom G6 CGM system without the need for fingersticks or calibrations.

When you start a new sensor, you must enter a code into your display device (and pump, if you’re using an insulin pump), as each sensor has its own code printed on the back of the adhesive patch. Make sure to follow on-screen prompts step by step.

Where should I place my CGM sensor?

Your Dexcom CGM should be placed on the abdomen. As an alternative site, patients aged 2 to 17 can wear sensors on the upper buttocks.

Choose a site:

  1. At least 3 inches from any insulin pump infusion or injection set.
  2. Away from waistbands, stretch marks, scarring, tattoos, irritation and bones.
  3. Unlikely to be bumped, pushed or laid on while sleeping.

Which insulin pumps will work with Dexcom CGM systems?

CGM therapy systems can be used with or without an insulin pump.

Current CGM/Pump Compatibility by Pump Manufacturer as of 2/8/2023:



 OmniPod 5


 Dexcom G6




 Dexcom G7




Why did my Dexcom G6 sensor fail after I started receiving readings from my current sensor session?

During a sensor session, your Dexcom G6 may detect that the sensor can no longer determine your glucose readings. At this time, the sensor session will end and your receiver or compatible smart device will display “Sensor Failed”. You will now need to replace the sensor.

To prevent sensor failures:

  1. Make sure your transmitter is snapped into the holder of the sensor.
  2. Choose a sensor placement site that is:
    1. At least 3” from the insulin pump infusion set or injection site.
    2. Away from the waistband, scarring, tattoos, irritation, and bones.
    3. Unlikely to be bumped, pushed or laid on while sleeping.
  3. Clean the insertion site with alcohol.
  4. Check the expiration date on the sensor. Don’t use it if expired.
  5. Check use-by date on the transmitter box. Start using the transmitter before that date.

Why isn’t my transmitter working and/or why is my Dexcom CGM System telling me to pair a new transmitter?

Dexcom G6 transmitters are under a limited warranty for the first 90 days from activation, provided that activation was within 5 months of the shipping date. You can find your transmitter activated date in the settings screen on your display device.