Possibly stupid question: How to see original transmitter start date on xDrip+?

I forget when I started my transmitter and am wondering how I can see its original start date on xDrip+? Or is there a way to see that it’s close to it’s 3-month mark? It’s super easy to see the sensor start date but I can’t find where the transmitter start date is, or the way to find out what it is.

If you go to the G5/G6 Status page you will see transmitter days somewhere at the bottom of the list.


@Headlands @Aaron gave you the best answer, but I have a further question.

Why do you want to know it’s 3 month mark? With xDrip+ the transmitter just keeps going until the battery dies, usually much longer than 3 months. No arbitrary 3 month cutoff.

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Most of this information should be on the “system status” or the “classic status page”; left of the former (right swipe). It’s a bit weird; currently the only way to find the true sensor start is on the “classic” page, despite the fact that this is clearly more relevant to us than the “sensor status” on the “system status” page which simply displays the time since the last restart. It’s obvious that the developers are fixing this, gradually; here is my current display:

There’s a lot more information in there (this is the “beta channel” release) and some of it, like the calibration code, can be very important to us G6 users.

@docslotnick says:

(Possibly stupid question: How to see original transmitter start date on xDrip+?)

@Headlands @Aaron gave you the best answer, but I have a further question.

Why do you want to know it’s 3 month mark? With xDrip+ the transmitter just keeps going until the battery dies, usually much longer than 3 months. No arbitrary 3 month cutoff.

Well, yes, but the transmitter is dirt cheap so there is no harm in replacing it after 90, or for that matter, 120 days and as my readout about shows after 67 days xDrip+ is registering low battery voltage under load on the transmitter while my sensor has been running for 17 days. I normally terminate my sensor with extreme prejudice under the waist-band of my kilt, but so far as I can see four sensors can easily cause a transmitter to start to flake out (cf recent discussions here about replacing the transmitter).

John Bowler

With all due respect, the transmitter is the single most expensive component in the Dexcom system, witness the numerous threads here on extending its life.


When I last filled my prescription at Walmart the transmitter (a 90 day supply) cost $295.21 and a box of sensors (a 30 day supply) cost $416.41, so the sensors are 4.23 times the cost of the transmitter.

CostCo prices have apparently changed recently, but the numbers from November 2018 (I think I posted these on fudiabetes.org) were $20.83 for the transmitter and $92.33 for each sensor; my suspicion at the time was that CostCo/Dexcom were selling the transmitter at cost (COGS).

The actual price ratios are all over the place, expressing transmitter costs as a percentage of sensor costs CostCo comes in at 3%, EdgePark at 40%. Even going through EdgePark’s fanciful prices the transmitter cost is significantly less than the sensor. This more recent article (January 24, 2019) repeats the CostCo pricing (approximately):

To get the Costco pricing, you of course need to be a Costco member ($60) and also sign up for their free pharmacy program. From there, Dexcom confirms that the cost savings are enormous:

The April 1, 2019 update (see the next paragraph in the same article) has these prices:

**** UPDATE:** As of April 1, 2019, the Costco Pharmacy membership prices have gone up according to the latest company infomation published online:

  • G6: Transmitter: $145.51 each
  • G6 Receiver: $218.27 each
  • Box of G6 Sensors (three pack): $318.10

And following that link to CostCo’s web site the prices are still the same today - no Bastille day savings. So the cost of the transmitters vs the cost of the sensors as precentages:

CostCo (pre April 1): 3%
CostCo (post April 1): 15%
DexCom: 22%
Walmart: 24%
EdgePark: 40%

I draw two conclusions, firstly the manufacturer recommended price, used by Walmart, makes the transmitter just under one fifth of the total day-to-day cost (18%). CostCo reduces that to 13% and EdgePark hikes it to almost 30%.

When I extend the sensor by doing restarts with xDrip+ I don’t, so far, achieve more than a doubling of sensor life with failures being 50/50 mechanical (adhesive failure, wardrobe malfunctions) or transmitter reported sensor failures.

When I look at the product I see a sensor which is way more expensive to produce than the transmitter; I suspect this is why CostCo were able to achieve the pre-April pricing because I believe that the transmitter is basically a give-away, like blood test meters vs the strips. I’d calculate the BOM cost of the transmitter to be a few bucks at most. The new box-in-a-box packaging I received from Walmart looks horribly expensive to me but I suspect speciality pharmacies may just be shipping the inner box (no instructions).

Long term I wouldn’t be surprised if the pricing reverts to the pre-April CostCo 3% across the board. The main problem with the transmitters is shelf life; the battery is always connected and in my order from Walmart the transmitter shelf life is to 2010-01-13 while the box of sensors (1 month supply) is to 2020-05-04. Dexcom needs stock to shift off the shelves regularly so are motivated to having the transmitter turnover work much more reliably than the sensor turnover because of the shorter shelf life.

I will certainly be getting new transmitters as often as my insurance company permits whereas replacing a sensor every 10 days is a PITA because of the 1 day of squirrelly readings, and two hours of no readings.

John Bowler

@jbowler I think we may have a disagreement on whether $295.21 is a “dirt cheap” amount of money. For people trying to extend their transmitter life so that they can affordably use the system, I suspect it is not.


It’s $1.62/day for someone in the US without insurance who only uses the transmitter for 90 days. People with insurance pay more at the start of the year but less after (in my case) six months; I’m paying $0 for everything now. It actually works out the same from Walmart (with insurance) vs CostCo (without)!

The sensors have a similar math, though it’s not a factor of two (more like 1.5 times more expensive with insurance, therefore insurance ends up being 75% of the non-insurance cost over a year for me.) The sensor is $9.23/day (without insurance), so the total cost per day is $10.85 assuming you use xDrip+ (“free”) on a cellphone you already own ($500 or so, about $2/day).

People without insurance who went out and bought two transmitters before April have got a six month supply for $40-$50; that’s what I meant by “dirt cheap”; 32¢/day. Dexcom could package a transmitter with every box of sensors, but that would probably mess with their manufacturing logistics and it would force them to use the transmitter shelf life (actually 8 months, 244 days) for the sensors too.

However this is moot for those of us with insurance; the artificially inflated prices mean that anyone with both a pump and a CGM who is covered for both through insurance will pay (insurance+$6500*(1-HSA adjustment))/per-year. In my case (I actually have a $6,000 OOPMax and I use my wife’s HSA too) that works out to about $14,000; about $40 per day, it’s somewhat less for people with lower income because of the insurance rebates.

It is, of course, completely different with Medicare Part D, indeed, the inflated prices are there specifically to allow providers and insurers to charge the government more for medicare, but as others have pointed out all you have to do is tell CostCo you don’t have insurance to get back to the $1.62 transmitter price; hardly perfect but it does work, just like buying test strips on Amazon.

Sure, you can save, what, maybe $430/year if you can manage to replace the battery three or four times in a single sensor. Ok, nothing to be sneezed at, but if you got in to CostCo on March 31 and bought three transmitters ($90?)…

John Bowler

John Bowler

@jbowler Gosh, you make the cost of treating diabetes sound pretty cheap. I’m glad that it is so affordable, otherwise people might complain that they have trouble affording it.

I also suppose the cost of insulin is not a problem, because you evidently have a $0 oop.


Yes, my insurance covers insulin, but no - I have a $6,000 OOPMax, reduced somewhat because I pay it out from our HSA accounts so the actual amount I pay out of my pocket is more like $4,500, maybe less because IRC my marginal rate was closer to 35% last year (10% to Oregon).

In other words my OOPMax is only a little better than anyone else’s; the maximum it can be is $7,900.
However, because I’m using a high deductible plan “HDHP” (necessary to get the HSA - which saves me $1,500 a year) I’m actually playing lower premiums than people on ‘silver’ plans:


This is why I say that this discussion only matters for T1Ds without insurance, and maybe those who are “covered” by Medicare, who are looking at paying $4,500/year for a CGM. Those of us with insurance will max out if we use a CGM and a pump (well, at least Omnipod or similar).

To make the statement again, a different way; if you are a T1D with insurance using the full range of modern treatments you will meet the out-of-pocket maximum of your insurance unless you have one of the “cadillac” plans from an employer where the employer pays pretty much everything. As a result saving money on your treatment does not make any sense.

For example I use Humalog KwikPens to fill my Omnipod, these are more expensive (though only slightly) than Humlog in a vial, but I avoid needing to carry extra supplies other than pen needles to handle an Omnipod failure. If I didn’t have insurance I would use the newer lower priced psuedo-generics being produced by both Eli Lilley and Novo and use vials. (Actually I’d be really tempted to swap to Walmart’s ReliOn which is Walmart branded Novo Humalin, but that’s a treatment change.)

If you choose your plan right your actual annual health care expenditure will be no more than your insurance cost plus $6,750 (mostly before tax) for an individual (ACA) plan. For a group (employer) plan the cost will be no more than whatever you contribute to the insurance cost plus up to $7,900 (after tax in this case!)

This is why in my case health care costs me about $15,000 per year. I suspect that figure is representative of people my age (59) and it certainly is the maximum anyone should be paying in south west Oregon, unless, of course, they try to dodge the insurance and end up with more than $15,000 of medical bills.

Here’s the link for next year:


I’ve never seen the point of “low deductible” plans, unless, of course, your employer pays. For individuals buy the cheapest HDHP that meets the HSA and/or ACA requirements. That applies to everyone, not just those of us who hit the OOPMax.

Pretty much any T1D who does two or more of the following must, I think, hit the OOPMax:

  1. Insulin analogs (Humalog, Lantus etc) or Afrezza (I’m not sure of the cost of that.)
  2. CGM
  3. Pumping (unless you are using an old pump and just getting the supplies.)

Then the annual cost will be:

Total of 12 month premiums, less rebate if you earn below 4x the poverty level;
Plus the plan OOPMax; no more than $6,900 for an HDHP in 2020
Less whatever tax you can recoup on that $6,900 through an HSA (there’s no point itemizing.) You can at least subtract tax on $3,550 or $4,550 if you are over 55 (both my wife and I are, so we will be saving in the HSA this year.)

The latter figure is a constant for an HDHP, so all you need to do is guesstimate your marginal tax rate (marginal - the amount of tax you pay on $100 extra income), subtract that off the plan OOPMax and add in the premiums. In November choose the lowest. Remember that the rebate you get doesn’t depend on the cost of the specific plan you choose, unfortunately it’s impossible to find until 2020 premium costs are set let in 2019; assume it will be the same as this year unless your income has changed massively.

You can also pay ACA premiums before tax if you have a business which is making a profit; the business pays the premium for you (on Schedule C) and deducts it as an expense, but that may compete with putting the profits into an IRA.

John Bowler

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Any costs can be made to look cheap if you convert it to costs per day :face_with_raised_eyebrow:


Honey, I’m home. I just bought a new Lamborghini Huracan! If I keep it for 40 years the cost will only be $24.65 a day… Wait a second that didn’t sound cheap. :slight_smile:


With xDrip select ‘System Status’. One of the items under System Status is ‘Transmitter Days’. If your transmitter was a Dexcom original then that will be accurate. If it is one that you replaced the batteries then it will be the total elapsed time for the transmitter. The System Status will also show the battery status. Right now my transmitter shows ‘107’ days. Also the battery resistance is about 1200 ohms, just about ready for replacement. I hope that answers you question.

I would think the transmitter cost would be absolutely the lowest cost item. If you change the batteries to the silver oxide cells it will last one year. I am speaking of the G5 transmitter with has two batteries in series. I suppose one transmitter will last for an indefinite period of time until a person breaks bonding wire. Dexcom only used alkaline batteries which I suppose is also used in the G6.