Costco and dexcom




Updating my comment some more. I got 2 transmitters at Costco for $41.77 (had to wait a day for them to get them from another store). When I got home I discovered I wasn’t saving as much money as I thought, although I saved money. I had seen that Edgepark wanted about $280 (after insurance) for a new order that included sensors, and I thought the sensors were about $40 of that. Turns out that the sensors were $225 (for 9)! I didn’t realize they were that expensive. I was used to paying $40 for a 3-month supply for the G4. 36 sensors a year would cost me $900 for what used to cost $160, although I guess I can cut the $900 by restarting the sensor. I haven’t done that yet, but my sensor runs out in a few hours, so I’m about to try that.

Now I’m not sure I want to bother with the G6. Other than saving me a few fingersticks when I start new sensors, why is the G6 so much better? It is coordinated with my pump and saves me from carrying an extra little gadget, but I don’t mind carrying an extra monitor. Besides, the G6 frequently shows out of range for 15 to 30 minutes at a time, and I don’t remember that the G4 did that nearly so much.


That would have to be your portion of the sensor bill with insurance picking up the greater portion. The G6 sensors are going to cost $100 per sensor at a minimum (IMHO). Sounds like your insurance may be picking up about 75% of the cost?

As you are using the Dexcom G6 and also using the Tandem t:slim X2 pump and mentioned that the G6 shows on your pump and given the only way to get the G6 on an X2 is with the update otherwise known as Basal-IQ then a natural follow-up question for me would be:

How do you find the Tandem Basal-IQ algorithm to be working for you?


This sounds like a fixed copay ($40 for 3 month) rather than co-insurance. Years ago I got this deal because they first classified sensors from mail order pharmacy same as BG strips (diabetes supply), not DME.
My price is much higher now, covered as DME, especially before deductible is met.

So odd if they treated G4 and G6 sensors differently. Or because integrated with pump, that changed classification to DME.


I may be stuck with the G6 (no pun intended) for now, as I just started with it in September and I doubt if I can get another G4 on insurance for a while. (I got a shipment of G4 sensors just before the G4 gave out, so I could use them. I’ve been planning to sell them, as I can’t do anything else with them.) I can try to stretch out the sensors longer and can even go now and then sticking my fingers instead of using sensors. I have a few items to investigate with insurance in the next week.

I haven’t used the Basal-IQ the last couple weeks, but maybe I’d better, as I’ve had more lows recently, but that’s partly because I’ve been using Humulin R in the pump. I get tired of trying to figure out when to change the infusion set with Humalog. If the site gives out early on the 3rd day, I don’t know if it’s what I ate or a need for a change in the site but I run high BGL’s for a while. If the site gives out in the late evening, I will have higher BGL during the night until I change the set in the morning. With Humulin R, I usually run 9 days before needing to change the site. So I have one site problem every 9 days instead of 3+. But I want to use some H to speed up when I can eat, so I supplement most pump doses with some H and usually use H to bring down a high BGL.

I didn’t like the way the Basal-IQ would shut off my insulin when my BGL was 130 and heading down, but I can override the shutoff. I’m still new with the G6, so I’m doing a lot of experimenting. I am happy to have BGL’s in the 70s, but Basal-IQ is set for higher than that. I guess I can try a week or two with Basal-IQ and compare it to the last couple weeks on Tconnect and see how much Tconnect cuts down on low BGL’s.


I’m going to find out.


IMHO it is not about what the BG number is when the Basal-IQ kicks in, but rather what happens afterwards.

Bear in mind that Basal-IQ was tested and approved for Humalog and Novolog. I certainly don’t know anything about Humulin R to be able to even guess how the Basal-IQ would work with with the Humulin R.
That being said, we are using Fiasp with the Basal-IQ (which was not tested nor approved for such) and we are really happy with the results.

Basal-IQ Technology uses a simple linear regression algorithm that predicts glucose levels 30 minutes ahead based on 3 of the last 4 last consecutive CGM readings. If the glucose level is predicted to be less than 80 mg/dL, or if a CGM reading falls below 70 mg/dL, insulin delivery is suspended. Insulin delivery resumes as soon as sensor glucose values begin to rise. Insulin may be suspended for a minimum of 5 minutes and a maximum of 2 hours within a 2.5-hour rolling window.


I am finally on the G6 with my X2 and Basal-IQ.
I am only on my first sensor (day 8) but the Basal-IQ part has been working pretty good for me so far.
I would think with R it wouldn’t react in time for a low.
But if it shuts off Basal at 130, that might actually work?
What length of time do you have your pump set for the R? Maybe setting it to a long enough time period will make it work pretty good with R?


That is great you have it all working.
It will be very interesting to see how this works for you.
Good Luck with it.

Note that the clip above is the complete description for the Basal-IQ rules.
IOB is not a factor in the Basal-IQ rules.
Modifying the Insulin Duration of action will not impact the Basal-IQ. This setting (Insulin Duration) impacts the IOB calculation which may impact the bolus calculation of a subsequent bolus.


I got my A1C and figured out that my G6 is understating my BGL. Tconnect figures would have called for me to have an A1C of about 5.2, but my reading (and I know that tests can vary) was 5.6.

But now I’ve discovered that apparently I should have been calibrating my G6. I did that yesterday and the pump kept me nicely in the 70-80 range last night, shutting off my insulin several times but quietly. I shut the alerts off. I think when I get new insulin that I won’t need the shutoffs as much. I was getting by on about 8 units of basal/day, but now am getting 11/day. I think the insulin was spoiled slight when it was shipped in the summertime. I’m getting new insulin pretty soon, and I’ll see if I go back to normal.

I don’t like the Basal-IQ to shut off my insulin when I am eating and my BGL is still over 100. I know my BGL is going down, but I also know that the food I’m eating is going to raise my BGL. So I’m learning how to work the Basal-IQ. Let it work, but shut off the alarms and be ready to override it when I want to run lower.


About 2 weeks ago Dexcom quoted $349 for a box of any type sensors. $299 if you join their auto-ship program.


IF I change from G4 to G6: As a cash customer, can I buy the G6 receiver and transmitter from CostCo without buying sensors from them?
And are their prices still: Receiver $35.96, Transmitter $28.88 (each?)?
Prices I was quoted for box of G6 sensors: CostCo $318.29, Dexcom $349 ($299 if on auto-ship program), my copay with EdgePark $145.80


Yes, you can get just these without sensors. As of last week, those were the prices I got.


Today I bought a G6 transmitter from Costco for $26.88. I ordered it on Saturday and it was in today. I was not asked about insurance. (I have a high deductible.) I will buy the sensors directly from Dexcom because the price differential on the Costco sensors is not as significant as it is on the transmitters and the Dexcom sensor cost will at least go towards my deductible.