“It’s a whole different world right now than it was even six months ago, simply because we’ve taken the financial viability question off the table,” Tandem’s Chief Administrative Officer Susan Morrison said during the company’s July 30 investor earnings call.

Rumored to be near demise just a year ago, Tandem Diabetes Care has made a remarkable comeback — with its share prices and net worth now surging, to become what Bloomberg describes as “one of the hottest 2018 stories in medtech.” Basal-IQ is the first of a one-two punch upgrading their devices within a year, as Tandem anticipates launching its next bolus-adjusting feature in 2019.

This comes just about a year after Tandem received FDA clearance for its Dexcom G5-integration with the touchscreen t:slim X2 pump that can be remotely updated from home (a first for the pump market), and it’s a big step forward for the company on the closed loop ( Artificial Pancreas ) technology pathway.

Tandem Diabetes Care, makers of t:slim insulin pumps, recently launched an exciting new feature that can predict blood sugars and automatically adjust insulin doses to ward off hypos and keep BG levels in range (!). Known as Basal-IQ, this much-anticipated feature is available on the t:slim X2 pump connected with the new Dexcom G6 CGM (continuous glucose monitor).

Next-Gen Automation: While Basal-IQ only tackles auto-adjusting background basal doses, and doesn’t touch on boluses for food or corrections, that’s not far off we’re told. Tandem hopes to launch in Summer 2019 its next-gen tech known as Control-IQ (aka Bolus-IQ but not to be confused), which adds on the bolus-dosing functionality. Tandem plans to start filing that data with regulators by year’s end, with hopes for FDA clearance sometime in the middle of next year. This would bring Tandem’s offering up to pretty much on par with Medtronic’s 670G Hybrid Closed Loop , the first auto-adjust system on the market launched this past year.

No Cost to Upgrade: The upgrade is free for those already using the t:slim X2. For those not on an X2 or yet using a Tandem pump, there’s clearly a cost associated.

Updatable from Home: If you’re already using a t:slim X2, you can just update that device to include this newest Basal-IQ feature! You will need to get a doctor’s prescription that includes a specific code in order to update this in Tandem’s system. And yes, as noted above, if using the earlier Dexcom G5 CGM, you will need to upgrade to the latest G6 version to use the Basal-IQ feature.

Mobile App: We’ve been watching this one for a while. While data-sharing and mobile app connectivity isn’t yet offered for the t:slim X2 or Basal-IQ, word is that Tandem’s working on this. In mid-2017, we reported that Tandem was hoping for a 2018 launch of its mobile app that would use Bluetooth to beam data directly from the X2 device to a smartphone, with alerts and reminders as well as auto-uploading to the t:connect software for display and data-sharing. While it wouldn’t be initially available, Tandem also had hopes to weave in a remote bolus calculator, auto setup features, real-time CGM data (instead of just retroactive), training and education materials, and more data-sharing features allowing for decision-support aspects based on pattern recognition. Fingers crossed we’ll see that soon… Of course, Dexcom customers can use that company’s Share app for cloud-connectivity providing data sharing with loved ones, parents, healthcare providers, etc.

Alerts and Alarms: Users can choose whether they want alerts to sound each time this happens, although the point is to have this management feature working in the background, to give us PWDs less to worry about on a daily basis.

Auto Insulin Shutoff: What’s even more unique is that Basal-IQ can automatically shut off insulin delivery when the BG level is predicted to drop below 80 mg/dL or if BG is currently below 70 mg/dL and falling. Instead of automatically stopping delivery for a set period of time, the system immediately resumes insulin once BG values are back in range and at a safe level again.

Glucose Prediction with Dexcom G6: This works specifically with Dexcom’s latest CGM model, the G6 just approved this year and launched in June 2018. What’s unique is that G6 doesn’t require additional fingersticks for calibration as previous CGM generations do, as FDA designated the G6 accurate enough to replace fingersticks in making insulin dosing and treatment decisions. With Basal-IQ, the CGM data is displayed directly on the t:slim X2 pump touchscreen with all the typical graphs and data displays.

Uses t:slim X2: Remember, X2 is the platform Tandem launched in 2016 as the basis for all of its future D-device updates. Most notably, it can be remotely updated from home so that customers don’t have to trade in for a new piece of hardware every time some functionality gets upgraded. The t:slim X2 form factor is not very different from the earlier t:slim models. (More basics on the pump itself can be found at Tandem’s product page ).

We reached out to a handful of folks around the Diabetes Community who are in their early days of living with this new Basal-IQ technology. We were amazed to hear so many glowing reviews, even calling it a “life-changer.” Here’s what these users had to say:

D-Mom Stacey Simms in North Carolina – son Benny diagnosed as a toddler in 2006

The words I would use to describe Basal IQ so far are ‘low maintenance and smooth.’ Once the software is installed, you don’t have to add any additional steps to your routine — love that! The very first night it suspended three times — no alarms, no lows and Benny woke up at 95. I keep asking him if I can see his pump to look for red lines! He’s already rolling his eyes at me.

Benny does not want to carry anything other than his phone and the pump and he’s used to basically no fingersticks now (we’ve been on the Dexcom G6 for a few months) so this system works well for him. He was very skeptical initially but admits it’s pretty impressive — less work for better results is pretty appealing to a 13-year-old!

We’re learning how to use Basal-IQ in the best way for us; he’s still treating if he’s dropping quickly and feels low, whereas I’d like him to try to wait it out and see what happens (but of course I can’t ask him to do that!). He went to a sleepover this past weekend where they had a couple of hours of swimming first. Normally we’d have adjusted basal overnight, but the system took care of it! My only worry was whether the Dexcom sensor would stay on in the lake (it did).

There have been zero rebound highs and overall, we’ve seen more in-range numbers just in these first 7-10 days. Excited to see if it continues!

The only downside is that you have to be able to afford the whole system. Tandem pump, Dexcom G6, etc. I feel really lucky to be one of the first to try it and I hope insurers realize the value.

Patricia Kasper in Bakersfield, CA – T1 for 53 years

As I’ll be marking 53 years with T1D in late September, I’ve witnessed much change in how it’s managed. The last thing I got this excited about was when I received my diabetic alert dog, a black lab female named Tzayle (which means “My Shadow” in Hebrew). Now, she has less to do because I am not going critically low anymore. Gone are the days I need her to fetch a juicebox out of the fridge for me. Because of her scenting ability, she is faster at detecting lows than the alarms on the Dexcom. But she is NOT faster than the Basal-IQ algorithm when it comes to predicting lows. By the time she alerts me, Basal-IQ already has me suspended, without me being any the wiser.

During my first several days running with this update:

It suspended my pump an average of 4 times per day, for an average of 17 minutes.

A few of those were for only a few minutes, several were for 45 minutes.

My average BG over those several days was 25 points lower than during the previous week!

Basal IQ has given me the courage to lower the lower threshold of my target range from 100 to 80. So my service dog is having to learn a new normal. She no longer has to ensure I eat something when my BG is in the 90s, because in the past, that meant I was headed for a problem. No longer is this the case.

This new Basal-IQ feature is also enabling me to more aggressively tweak my settings to eliminate highs. As always, some changes are spot-on while others, not so much. But now I have the confidence to try harder to get those better readings. My endo wants me to keep my A1C at 8.0 to prevent lows. I’ve never been happy about that target, but now I feel like I can do something about it. Now I can look forward, along with everyone else, to the approval and release of Control-IQ, at which point I think my girl will be able to retire and be a pet.

Misty Walker in Alabama – T1 for 25 years

I came from the day when a fingerstick took three minutes on a meter the size of a calculator, and correction doses did not happen. We lived with a sliding scale and only took insulin at mealtime, where we were told how many carbs to have each meal (GASP!!). I have lived in Alabama all of my life and have been blessed with endos who were up-to-date on the latest technology. I was actually the second person in Birmingham to receive a pump. At the time it was Minimed and the device was HUGE! I was thankful to have it though…

Fast-forward a few years and I now have a t:slim X2 with Basal-IQ.

I cannot say enough about how Basal-IQ has changed my life in just a short time with it! Before Basal IQ, I would hit the gym at 4 a.m. knowing that I’d: 1) Either have to eat more carbs to get through a workout and then I would burn out, or 2) Just be prepared for a Low. I’m just over a week on Basal-IQ, and haven’t had a significant Low since starting this. I am beyond happy — I am ecstatic! This is not a game-changer for me — it is a life-changer.

Jennifer Tress in North Carolina – T1 for 44 years

I’ve been a T1 diabetic since the age of 2, so when I was diagnosed, CliniTest urine strips were all we had to measure our glucose. To think that in my lifetime, we’ve grown so much in diabetes technology is just amazing. I’ve always been an early adopter of diabetes tech and been happy with the results that my first pump and the Dexcom gave me. Several pumps later and with the shiny new G6, I’m now fully integrated into the Basal-IQ system. Here my first impressions:

I can SLEEP! This is huge. I honestly don’t remember the last time I slept through the night. The first night with basal IQ I woke up, assuming I was low (as usual…I could never get my basal rate low enough overnight. The Tandem didn’t go low enough for me to avoid lows) yet it was morning and I was fine, with lovely red lines all over my pump showing me that it had done its job. I was hooked. It’s easy to use, and easy to override if necessary. The update to the pump went seamlessly. There are times I need to override it, for example if my blood sugar is 80 but I’m about to eat a meal. It’s two taps of the screen and no problem! Bolus delivered and everything is fabulous! Cognitively, I need to catch up to the tech. If I see my Dexcom trending down, even when Basal-IQ is going to kick in, I’m still having a hard time trusting that it’ll “catch” the Low and prevent it. I wind up eating to treat the impending Low, and then having to treat a high because basal IQ did its job. I need to trust the tech. It’s only a week in, but I’m getting there. When I do trust it, it works. This is the first new technology, since the Dexcom that I’d call a “game changer.” My average blood glucose before the pump (according to my Dexcom Clarity reports) was 147. Since the basal IQ, it’s 118. That’s huge for me. And motivating. It’s motivating to know that the Lows can be prevented. I can sleep, and do more… I don’t feel trapped on a roller coaster from over-treating Low (we all know the feeling all too well of eating everything in sight due to fear). This is the first time in a long time I’ve felt I’ve successfully managed this disease and have some control. It’s still like herding cats… but nicer cats. Manageable cats. 🙂 And that has given me the gift of hope. I’m excited to see what the closed loop will be like when it arrives, and for the first time I’m not skeptical. I’m allowing myself hope. For me as a diabetic, that’s rare.

Chris Wilson in Oceanside, CA – T1 for 21 years



I had already been using the Dexcom G6 for about two weeks when I was notified that the Basal-IQ update was available. Happily, once the update was installed on my pump and the transmitter ID entered, I just selected “Start Sensor” and the pump joined up with the sensor session that had already been started on my phone without a hiccup.

Basal-IQ basically does something that I had been doing manually for quite a while, so I didn’t anticipate a huge change in my Dexcom statistics. What I was looking forward to was a reduction in the time I spent monitoring the CGM and setting temporary basal rates on the pump. That goal was definitely achieved — I’ve since lowered the Low alert threshold, because usually by the time I get an alert now, Basal-IQ has already seen it coming and taken action. I no longer freak out when I hit 80, because it’s unlikely to drop below 70.

The rules for resumption of insulin delivery with the Basal-IQ algorithm are more aggressive than I could achieve manually, which has had the effect of dramatically reducing rebound highs, and consequently giving me increased time in range. I’ve already had a 48-hour period that was almost 95% in range, with no highs and no urgent lows.

I’ve also found that when I do over-correct a high, Basal-IQ is very effective at blunting the crash, and acting as a damper on the subsequent blood sugar oscillations that result from the over-correct/over-treat/over-correct cycle that T1s often find themselves in. I can get off the roller coaster and back to being stable and in-range much more quickly.

Obviously, it’s not perfect — it can’t do anything about a late Saturday night burrito run that I foolishly under-bolused for; but the Basal-IQ algorithm is much better at what it does than I am when I attempt to do the same thing manually, and I’m still seeing unexpected benefits on an almost-daily basis.

D-Mom Samantha Merwin in Connecticut – son Logan diagnosed as a toddler

This is truly a miracle for us! We used this during the clinical study, and now we’re so thankful to have Basal-IQ back in our lives after handing it back to the trial coordinator eight months ago. We love every minute of it! Seeing the CGM graphs (via data-sharing) when Logan’s at school makes me emotional sometimes, as I know that he’s feeling so much better not having those lingering lows at school and staying in his preferred range.

It’s been incredibly amazing at night. He loves waking up in the morning and looking at the pump to see how many times it suspended him. The integration with the G6 is life-changing for him.

I was skeptical the first few days about not calibrating, so we wore the G5 + G6 and did fingersticks to double-check accuracy. The G6 was right on target and he happily ripped off the G5. The insertion is so easy, not having to calibrate is a breath of fresh air, and not having to test as much will hopefully give his fingers a rest after 10 years of finger pricks. We still have him test in the morning and at night, or if it says he’s under 50 or above 300, but so far it’s all checked out. I’m not trading in my Juicy Juice subscription yet as those super-fast activity Lows sometimes require action. But the system catches and corrects an overwhelming majority of our Lows which has improved his quality of life. And mine.

Brian Mozisek in Katy, TX – T1 for 24 years



Given that I was diagnosed in college, I was taking care of myself from Day One, when I went back to college two weeks after my diagnosis. I started on a Minimed 506 in 1996, then moved to the Animas R1000 in 2000, Deltec Comzo in 2004 and 2008, Tandem t:slim in 2012, and finally the Tandem t:slim X2 in 2016. I also tried the Abbot Navigator CGM for about six months and decided that it was not worth the time, money, or effort. I started on the Dexcom G4 in 2015, upgraded to the G6 in July 2018 so that I could get comfortable with the new sensor and no calibration requirements before Basal-IQ went live.

I received the Basal-IQ update on August 21st. I’m really liking how it works. It does a great job when I’m changing my activity levels. I’ve had two cases when I still had to take fast-acting carbs, because I miscalculated meal boluses.

The first day that I updated my pump, I went to my son’s soccer practice and watched it suspend when I was around 150 mg/dL. My BG continued dropping, but then leveled out at 100. Previously, I’d have programmed a temp basal rate and later I’d have a rebound high because of the lower insulin. With this new Basal-IQ, I never had the rebound. Ive also been able to sleep much better. There are usually 1-2 suspends per night, but some nights, I will have several. I have seen it stop a BG drop, which I would have previously treated, and then keep my BG between 80-100 by suspending several times over the course of several hours.

With Basal-IQ, I have been more aggressive in treating highs. I did have Basal-IQ fail to stop two lows from happening. Both of them I had IOB (insulin on board) due to overly aggressive treating of post-meal spikes. One alert that I wished Basal-IQ had was an alert when either it doesn’t think it will catch a low, or when it suspends with IOB active. Right now, there is only an alert when it suspends or resumes insulin. I have both of these turned off because I will have several of these during the day and do not need them.

Using Basal-IQ does require a change in mindset to let the pump do its job. Based on how this is performing, I cannot wait until Control-IQ is released next year.