Dexcom G6 and IOS Versions

I use my iPhone XR with Dexcom G6 and Omnipod 5. I usually update the phone when new IOS versions come out. I’m currently using IOS 16.4 to which I updated recently. Also recently I’ve noticed pretty big discrepancies between the G6 readings and finger sticks, often 60 or 70 points.
I checked with Dexcom and see that the G6 is only compatible with up to IOS 16.3.1. I talked to several people at Dexcom and all said that using the incompatible IOS version may be the cause of the inaccurate readings on the phone. It may work, it may not at all times I was told. I was also told that Dexcom put in a request to update the compatibility to the latest IOS version, 16.4.1. But who knows how long that’ll take to get done?
I’m trying to avoid having to carry the Omnipod PDM, my phone and the Dexcom controller.
Has anyone dealt with this by downgrading their IOS version to 16.3.1?
Thanks, Mike

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I’ve been on iOS v16.4 since last Friday and it seems to be working fine with Loop. I changed sensor and transmitter a few days ago. Thanks for pointing out the potential issues with the Dex app. I will keep a closer eye on my Dexcom results!

Your Omnipod get data from the Dexcom Transmitter. Compare the readings on the PDM when you get home with the Dexcom G6 app on your phone. They should be close. I haven’t figured out if the value smoothing Dexcom does is happening in the transmitter or the G6 app.

I wouldn’t blame software for what can more often be explained by interstitial fluid. Dexcom does not validate all versions of iOS. Their update to support iOS 16 came after 2 years of not validating compatibility. For CYA legal reasons Dexcom support can’t say an OS version should work.

I’m also not going to tell you that 16.4.1 will work fine. I will say that like you I update regularly because an exploited iPhone is a bigger problem for me than Dexcom having a problem.


I have an iPhone 11 Pro Max, Dexcom G6, and Omnipod Classic.
My iPhone is still currently at 15.6.1
The Dexcom is always behind in their updates, as this is why I haven’t updated further. Newest is 16.4, & currently my phone would only be compatible to 16.3.1
So I feel frustrated that if I were to update my phone, it will automatically update to the newest version & not the one Dexcom will support.
Any suggestions?

Hi Andrea,
I read that you when you open the update screen it’ll give you a list of updates that are available, and you can choose the one you want. I’ve never seen this since I’ve never had more than one update available.

Recognizing that this is only my personal experience and others may have different experiences or views, I’ve not had any problems with iOS updates.

And I’m always updating as soon as the next refresh comes out. With Dexcom or really any apps running on my phone.

But that’s one reason why I’m an iPhone fan, not that I love apple necessarily, but because it seems that it’s more of a controlled environment it is more stable.

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That seems really weird to me. Can’t imagine by what mechanism an operating system would change the numbers within an app but I’m far from a tech expert.
The thing that’s not clear to me from your post is whether the Dexcom reader is giving accurate readings while the iphone is giving inaccurate ones. I have occasionally seen a passing discrepancy between my pump’s reading of the Dexcom and my phone’s reading of it, but they are rare and usually only involve a flat arrow vs a trending down arrow or something.

Tnyc, no, I haven’t noticed any discrepency between the Dexcom and Omnipod readings. The difference is between my Freestyle Lite BG meter and the Dexcom and Omnipod.

And the answers I received from the Dexcom techs were not very definitive. I think they’re covering their backsides by saying don’t use the Dexcom phone app if you have yor phone updated to anything beyond ver. 16.3.1.


From Dexcom,”Dexcom is compatible with iOS 16.x”. That means act revision of iOS 16.x since shortly after that version of iOS has been released.

Ah. Very interesting. I thought we only needed to be concerned if the ios changed to like 16.5 … When I changed my last sensor (having it on for 10 hr prior to adding transmitter) it seemed to be off more than usual, but now that it has been on a couple of days, it seems ok.

Oh, yes. That is what I meant!!

Like going from iOS 16 to 17!

Dexcom has only ‘tested’ to whatever version. On the flip side, Dexcom must continue to support versions of iOS at its current level. Failure to support the current iOS is opening the door to malware and other operating system issues.

Your report about inaccuracies is just that. I was in a clinical facility and had to have anesthesia. My Dexcom G6, fingersticks, and lab glucose were all within ±5mg/dL throughout my time in the facility. Fingerstick to CGM were never off by more than 2mg/dL. The lab blood glucose was 97 when finger stick and CGM were 101.

Mike, as far as backwards version movement, you can’t do it. It will render your iOS device a paperweight. I do software beta testing and can tell you, DON’T TRY to go backwards.

Reading your post leads me to believe you are having other clinical issues. Remember, only do finger sticks when your CGM has been level (>±5mg/dL) for the previous 5 CGM readings, otherwise, you are not allowing for glucose mobilization stabilization.

Upgrade to iOS 16.4.1 for your device security and stability. I have been using 16.4.1 in beta and since public release. The 16.4.1 is rock stable and works well. I use Tandem tConnect, Dexcom G6, Dexcom Clarity, SugarMate, Tidepool, & Glooko on my iPhone 12 Pro Max.

Hope this helps.

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Interesting to note I have a 7+. Ver 15.7.5 which apple says it up to-date.
The only issue I have is with Dexcom Share not staying on line even when both phones are in the Sam room. Early one my wife could be across town and know my glucose level.

Now at version 15.8.1. No issue. Found out the share dropping out is due to the VPN I have…
Shutting down the VPN at night, now allows me to use the Sugar Pixel display. It’s a clock like display that shows my BLOOD SUGAR VALUE. Share sends the value to the follow app.which send it via WiFi the display. No more fumbling with my iPhone to see what my BS is at night. The VPN was dropping out WiFi at night.

@John70 , the current iOS is 17.3.1 with 17.4 expected Tuesday of next week March 5.

Most iOS updates are to block new malware or computer viruses. For your phone security, update.