Dexcom CGMS

I never expected to be approved for a CGM. I have had good control with A1c’s below 6.0 for several years but I still have a few highs and lows that are unexpected and want to know they are coming before they arrive. My endo is very cooperative and wrote a letter to my insurance company. I was required to send my charts showing my BG tests for the last 6 months. My endo faxed them to my insurance company and I was approved for the Dexcom CGMS. Unbelievable!!!

I have seen the Dexcom site and the tutorial video. It seems to be easy enough. I want to know how successful you folks have been with a Dexcom. I think some of you are using one. Any suggestions, strong/weak points of the Dex? Thanks for any help you are willing to provide!


I’ve been on the Dex for about 8 months now, and love it.

Like you, I’ve been in very good control and that kept me from getting approved for quite a while Most of my A1C’s have been 6.5-6.7. On the Dex, I’m now 6.1-6.2.

Pluses: The wave… you know if you’re climbing or falling. I’ve stopped a lot of lows by being 80 and seeing the arrow trending lower. Very cool. Also, you can pinpoint basal rates.

Minuses: It’s a second device hooked up to you, which is kind of a pain. When the new Animas pump comes out next year with a CGM receiver built in, I’ll go for that one. It will use the Dex sensor, which is very comfortable.

Other minuses? It’s not nearly as precise as an insulin pump. In terms of being accurate at trending, it’s awesome, but is often off by 20 points or so compared to a blood sugar meters. Also, it’s new technology… Probably 20% of my sensors fail in less than a week. Dex replaces them, no questions, asked, but you need to call them.

I love it, though, and am very glad I went on it.

I’ve been using the Dexcom for almost two years, but not constantly. I use it when I feel like I’m losing control because it helps me get back on track and I use it to prepare for an endo visit so my doctor can see my nighttime bg levels or my CDE and I can discuss trouble spots, if any.

I agree with Marcus’ plus and minus list for the most part. It can be irritating to carry an additional device around. In addition, the alarms are VERY annoying.

I don’t agree that precision is a minus. All CGM makers are up front with the fact that the number you get from the CGM is imprecise and not good enough for making a treatment decision. (Maybe because the FDA makes them say it - I don’t know.) In any case, one of the hardest things to learn as a new CGM user is to quit obsessing over the fact that the CGM number doesn’t match the meter number. They will rarely match precisely, although it is a thrill when they do.

The point of the CGM is NOT to know what your BG is at the moment but to see how it’s trending. Is it staying level? Is it going up or down? How quickly? What affect did my last meal have on my BG? Did I bolus correctly for it? That kind of stuff.

If you keep trying to chase the meter number by constantly recalibrating your CGM to get it to match (as I did at first), you’ll just end up frustrated. A solid trending line is what I really like to see. If the points are jumping all over the place, it’s either a bad sensor or time to replace an old sensor.

If expense is an issue, you can re-use the sensors beyond the 7-day period. You don’t remove it and reinsert it, just re-start it AS IF it were a newly inserted sensor. Results will vary by sensor. Sometimes you’ll get two or more uses out of it, sometimes one and a half. If you are restarting it, one of the common causes of failure is that the adhesive comes loose and the sensor falls out. So be prepared to use some extra tape or Tegaderm.

Finally, be careful not to put your receiver in the washing machine.

I’m just saying.


Richard, congrats on all accounts !!! ( mainly because you " belong " to the Senior Pumpers group :wink: ) …I am not a Dexcom user, so will leave comments for those , that have .

Richard, what’s your insurance?

I’ve asked my endo to write the letter to AvMed, who says it will not cover CGMs. I really would like to use it since my BGs trends are very hard to decipher… thanks

I am age 70 now and have Medicare but they would not cover my pump or CGM. My secondary insurance is the New York State Empire Plan. That insurance covers my pump and my CGM and all the supplies. My doctor really helped with this by writing very convinicing letters. That helped very much!

Thanks Terry and Marcus for your helpful information!


My A1C was not as good as yours before I got my Dex. 5.8 give or take. After 6 months with the Dex my A1C is 5.2 with greatly reduced highs and lows. My Dex is so accurate that I prick my fingers only twice a day for calibration. My sensors don’t fail and I use them for 12 days. The beginning of the 2nd week is always the best in terms of accuracy.

It took me about 3 months to get the hang of it. The delay takes getting used to.

Calibration is a finicky subject. Read Rick’s threads. This can save you some frustration. Or ask me. I am more than happy to share whatever I know.

Good luck.

Thanks Helmut, I may be sending you a message later on, after I get started. I just noticed a few minutes ago that there is a Dexcom users group. I am going to join that group now.

Congratulations! Is your approval through your Medicare secondary insurance? I haven’t tried lately to get approval for cgm through my secondary. It would be nice if medicare is finally recognize that some of us are serious about managing our disease. Over a year ago I received an email that Medicare had code number for cgm but still wasn’t approving…hopefully they are now.

Earlier this year I tried the Dex com through Gary Scheiner’s office and it was very helpful in warning me of lows before they registered on my meter.

Betty, Medicare rejected my pump and my CGM. My secondary is The NY State Empire plan. It is covering both my pump and CGM. Medicare seems almost useless at times.

Medicare didn’t pay for my new pump but my secondary ins. did. When I applied for cgm my secondary said whatever Medicare approves then they do the same. In other words the secondary pays for what’s called durable equipment. So if your secondary paid for your pump then they are also paying for your cgm, so I will try again with mine. I hope I’m interrupting this correctly…Medicare is so convulated and confusing when I think I’ve got clear understanding then something else appears…it is such a maze. But thank you for sharing your information.

Betty, my doctor wrote a very convincing letter to my insurance company. I think that carried a lot of weight, especially since she is an endo. My sending my BG listings fpr the prior 6 months helped too. That was my endo’s idea.

I’m sure that my Endo will cooperate and send info if I ask him. As you might be aware the new MM 522 has a record keeping feature and I do use it to upload my bs record to my pump. When I first got this pump and Gary suggested to activate the Bolus Wizard I was hesitant but now I’m glad I did. There are times that I have to send a record to Medicare to justify why I need so many glucose strips and all I have to do is upload my pump into my computer and print…woohoo I love technology.

I inserted my Dexcom on Thanksgiving Day (I know, I know…) I love it! I quickly learned to let my body adjust to the sensor. I change it late in the evening so that by morning I’m pretty well adjusted. It seems as though my readings are spotty for the first hours. I was convinced that it wasn’t going to work and because it was T-day, I couldn’t call the Tech Dept! :slight_smile:

My sensor failed on day 3. I shut it off and restarted it…and it worked fine after that. Last night someone from Dexcom called me (A trainer I believe) so I’ll call her back…but after 2 weeks, I feel pretty comfortable with it. I had a lot of questions, but I figured it out with the forums here and some patience! :slight_smile:

The charts you can print out are amazing. I have learned SO much in 2 weeks about the way I react to food. I wish I had this sooner.

Best of luck to you and please post any questions you have. I’d be more than happy to share my experience with you if it could help! :slight_smile:

Thank you so much Beth, you are very kind!