Tandem Control IQ

Has anyone received the Control IQ software update from Tandem?

I contacted Tandem the week before last and started the process. They indicated that they need a script from the endo. His office indicated that they sent it to Tandem a day later. That was about 10 days ago.

I called Tandem and they tell you to go to the portal for updates. The portal indicates that I am in the “Prescription Waiting Period.” It has been in this state for over a week.

What gives?

I would say they are probably overwhelmed which happens each time they have an upgrade available. Sorry it is taking so long, but I can’t say I am surprised. My guess is they have a human entering the prescriptions manually to allow you to access the download and they probably got 100x what they normally do, which could easily be a couple week backlog. I myself hate waiting, but that may be your best bet.


In addition to the release of Control-IQ, for us old timers (AKA Medicare-eligible folks), Dexcom and Tandem are in the process of upgrading G5 folks to G6 which makes us eligible to then download and upgrade our pumps to Basal-IQ. That has been going on, I think, for the past couple of months as each Medicare-eligible t:slim X2 user’s G5 transmitters expire. In other words, Tandem has TWO upgrades in process at the moment.

I just went through the G5 to G6/Basal-IQ upgrade process.

My timing was as follows:

I applied for the upgrade on Jan 14. Tandem contacted my endo on Jan 14 and received their response on Jan 15. Note: having your endo send in a prescription in advance doesn’t help because there are several bits of information that Tandem needs … at least for Medicare. Once Tandem had the info they needed from my endo, I received email notification that I could start the online training … that was also on Jan 15.

I didn’t go through the training immediately, but must not have waited too long because I received notification on Jan 17 that I could download the G6/Basal-IQ update for my pump. So, for me the process only took 3 days.

While this may not be the precise timing and/or process for the Control-IQ upgrade, I hope that this will be at least marginally useful until someone who has equivalent Control-IQ upgrade process and timing information.

Best of luck … until CMS approves Control-IQ for us old codgers, I envy you youngsters that can already upgrade to Control-IQ!



Medicare has nothing to do with being able to download control-iq. There are numerous Medicare patients using control-iq from the first day it was released.

I got my update email on the 21st, received the link to the training videos on the 22nd, watched the videos and got the update code 10 minutes later.

1 Like

There is also a Basal -IQ update in the works too. Sounds like the timing of new features\upgrades\ new accessibility is more than Tandem can handle at the moment.

1 Like


Thank you for that information. I would be thrilled to be able to now upgrade to Control-IQ as well.


1 Like

There were quite a few people that never got the email and couldn’t start the update process because the portal system needed to be reset by a Tandem employee. They called Tandem, got the glitch fixed and could then start the control-iq update process.

1 Like

I was one who did not get the email. Today I tried to call and they are completely overwhelmed, so they send you to the web site. And this time the site let me say I want to upgrade, and I got all the way through to the “You need a prescription” page. My endo’s practice has given Tandem blanket upgrade approval for all their patients, but I will have to wait anyway.

Tandem’s automated email ack said they will email me when they get the prescription and:
Our Customer Technical Support is currently experiencing high call volume. Please help us keep the phone lines open for patients who may be experiencing a disruption in insulin delivery and allow us time to process your prescription.

Edit on Feb 3: got my email, jumped through the hoops, and UPDATED MY PUMP! The process was very smooth. The online course you take was excellent, increasing my understanding of how the software works and my confidence that I know what I’m doing. Had to take my almost-full reservoir off, but just loaded it back on and only lost the minimum 10 units for priming. Sleep mode disables correction boluses and only adjusts basal, so don’t think that will work for me but might be nice for flatliners who really didn’t need Control-IQ very much in the first place.

1 Like

Sorry, that really sucks. Hope you get the upgrade soon and report back how it is working. We are holding off since Basal IQ is working so well for us. Might do it on Spring Break or some time when my son has some patience to learn the new approach, including tips and tricks and such.

Do you have any concern that you can’t go back?

Generally the way insurance for insulin pumps works, you get a new pump every 4 or 5 years. I am wondering if you were close to getting a new pump, if you could keep the old one and just wait until you get a new one and only upgrade one of the pumps.

Is that possible?

@Chris I had the same concerns about control-iq. I was worried that it would not work as well as basal-iq to prevent low BGs. I was wrong, control-iq works better than basal-iq.

Control-iq is not without its own issues. I hated it the first few days I used it. My biggest complaint is the algorithm does absolutely nothing until the BG reaches 180. The 30 minute minute predicted time frame does NOT prevent the BG from spiking. Once you’re at 180, you’re going to have to manually correct because the pump does not ward off high BGs like they’re advertising. In my experience, control-iq added more frustration and work to get my blood sugars down. Having a dead zone of 111-179 where the pump does nothing is ridiculous.

In my frustration, I activated sleep mode to run all the time. After making this change, I can honestly say it’s a completely different pump now. Because the control gets tighter in sleep mode, 110-120, I’ve had few issues now. You do lose the automatic diminished bolus in sleep mode, but the algorithm is so aggressive with basal rate adjustments, it’s a non issue. For some reason, a Tandem CS rep just had to tell me, I’m not allowed to use sleep mode all the time. She did not like my response

Give control-iq a try. You can go back to basal-iq, you just have to call and request it and they will add an option to download basal-iq in your portal.


That’s hilarious!

What is automatic diminished bolus?

1 Like

@Eric when running control-iq in regular mode, the algorithm will give an automatic bolus once an hour for a BG over 180, at 60% of what a normal bolus would be. As an example, if my BG is 180, I would need to bolus 2 units for my 1:40 ISF. The algorithm only gives a bolus of 40% less than the user would require, for that same 180 BG, the algorithm would bolus 1.2 units. Once the BG goes below 160, it ceases to adjust basal rates.


So if am understanding this correctly, you lose that in sleep mode. And in sleep mode your BG is only fixed by basal instead of bolus?

But what difference does that make? Adjusting basal or giving a bolus, either way you are getting more insulin. So it essentially does the same thing for you, right?

No. Sleep mode adjusts basal rates constantly to keep the BG between 110-120. If you’re predicted to go below 110, the pump will drastically cut back basal rates and will suspend delivery if the BG is predicted to fall below 70. This portion of the algorithm is phenomenal. If the BG is rising above 120, the basal rates get crazy to get the BG back into range.

With native control-iq, the pump does absolutely nothing if the BG goes over the target of 110, and doesn’t start to adjust basal rates until 160. Once the BG reaches 180, it will continue to adjust basal rates and give a bolus. Again, the pump doesn’t start to fight the BG if you’re between 111-159. Where as sleep mode is constantly working to keep the BG between 110-120. With raising basal rates up to 15 units an hour max, it brings the BG down much faster than regular control-iq with the bolus feature.

In the first three hours I used sleep mode, the pump adjusted my basal rates 60 times. The lowest was 0.167, the highest was 3.348


Well that gives me some confidence we might be able to use that to good effect. Please keep updated on any other tips or tricks. Also, knowing we could downgrade with push us over the edge at his next appointment.

1 Like

@Chris If your main concern is preventing low BGs, update to control-iq. The algorithm is more aggressive and gives a softer landing instead of just cutting delivery at a predicted 80 with basal-iq. Control-iq will resume delivery again with a very moderate basal rate to make sure the BG doesn’t rebound to much. I’m very impressed with how this works. This part of the algorithm works the same in both native and sleep mode. I’m absolutely loving how well the pump is managing my blood sugar now that I’m in sleep mode all the time.

1 Like

I got the Tandem Control IQ. You have to go through a cartridge change when uploading the software so there may be another delay before you get up and going.

How does it work?

I concur with other comments above that it does not do much to deal with higher BG levels until you reach 180. That is a bit of a disappointment since I would like to stay below 180 if possible, preferably below 150 for most of the time. I intend to see how it operates using continuous sleep mode as recommended above.

At least to me, the Control IQ seems to work about the same as the Basal IQ on the lower BG side.

In summary,

On the positive side, it works just fine.

On the negative side, not as tight of control for higher BGs as I would prefer.

1 Like

I am a bit puzzled by the overall logic on this. Can someone perhaps get into Tandem’s head or the FDA’s head and explain it to me?

From reading all of this, I see that in sleep mode, they are more aggressive with your BG, trying to keep it between 110 and 120. In awake mode, they let it go up to 160.

But it seems that when someone is awake, you should be able to safely be more aggressive than if you are asleep.

When you are awake, you might feel a low more than if you are asleep. Like if the sensor was off and it was messing you up for example, when awake it seems like it is safer to be more aggressive than when sleeping.

So why is Tandem more aggressive when you are in sleep mode than when you are awake? this doesn’t make sense to me.

In my experience, the most risky and dangerous time for a diabetic is when he/she is asleep - not feeling lows, not waking up to a CGM, etc.

Any explanation or guesses for that? Why are they more aggressive when you are asleep?!?!


@Eric Sleep mode was designed specifically to combat dawn phenomena. I don’t think the engineers imagined patients using it 24 hours a day. From the limited discussions on other forums, a large portion of patients are using sleep mode all the time. I would not be surprised to see Tandem try to limit this function in the future by the response I got when I said my pump is in sleep mode all the time.