FreeStyle Libre 2 and 3 vs Dexcom G6 Accuracy

I used the Dexcom G4, G5, and G6. I found the G4 and G5 to be inaccurate. I find the G6 to be fairly accurate. I found the FreeStyle Libre 1 to be inaccurate. I found the FreeStyle Libre 2 to be more accurate than the 1, but not great.

Personally, I’m a T1 with hypoglycemic unawareness. So, the alarm feature while I’m sleeping is really important to me.

The FreeStyle Libre 3 was approved in Europe recently, which has a continuous reading with alarms like the Dexcom G6. It may be available early next year (2021) in the U.S. The big difference is that the Libre 3 will be affordable out of pocket. I have not been able to get Medicare coverage for any of my devices including test strips. They keep saying that I don’t have any equipment that uses test strips. Maybe it is because I live in NY. The Omnipod is not covered by Medicare.

What is your experience and accuracy with devices you have used?

I have personally found the Eversense to be the most accurate, and then Dexcom. and libre, but have found all 3 are accurate enough for me with a slight 20 min delay if I’ve recently injected insulin or eaten a meal, however, I have found different medications such as ibuprofen, naproxen sodium, and antibiotics can drastically affect Dexcom and libre more…might want to look into contraindications

I use finger sticks for insulin dosing. I use the alarm to alert me to hypoglycemic attacks.


Dexcom G6 is covered by Medicare.

Prior to G6, dexcom G5 was also covered, but required bg meter checks, and dexcom would send both G5+contour next strips.

But since G6 uses a code per sensor, it is considered just as accurate as bg testing, and covered by dexcom.

Contact Dexcom to check why you are being told G6 is not covered.

To get coverage for test strips, you may have to first buy meter covered by your MC plan and then get strips under Part B.

Every time I talked to someone at Medicare, I get a different story. Other people in NY have similar problems.


i would try to ask for freestyle neo test strips because the libre 2 reader is also a freestyle neo glucometer… the libre 2 also frequently requests you to check your glucose, and it might be convenient since you have to have the libre 2 reader on you at all times… my drs offered to write a neo test strip prior authorization form since my current insurance company prefers one touch, but I rarely use them with the cgm

They won’t listen and don’t care. I have tried for years and I finally give up because it is too much aggravation. They get on the phone with an attitude that their coffee break is being interrupted.


@DrJohn, I have been using G6 since it came out. I started with the Dexcom 7 in the early 2000s. I have continued to read peer reviewed journals, some juried included to harvest information about accuracy. Dexcom has always been the leader on accuracy.

The only down side is the range. I was hospitalized and had daily chem panels with glucose determinations. I had my G6 on. The serum glucose was consistently 14 mg/dL lower than the Dexcom at the time of the venipuncture. The nurses were impressed.

Hope this helps. Let us know what you decide. It is how this community learns.