The Tandem Mobi is a miniature durable insulin pump from Tandem Diabetes Care that delivers insulin through a short infusion set and is controlled primarily through an iPhone app. As the smallest fully featured insulin pump available, it offers the benefits of automated insulin delivery in a discreet wearable form.
What Makes the Tandem Mobi Unique
The Tandem Mobi stands out for its size, its iPhone-first control model, and its compatibility with Tandem’s Control-IQ automated insulin delivery algorithm. The pump is about half the size of the Tandem t:slim X2 and roughly one-third the size of older pump models. It attaches to the body using a short tubing set and adhesive patch.
Unlike Omnipod’s tubeless patch pump, the Mobi uses a short tubing connection. This hybrid design offers the benefits of a smaller pump that can be worn in a pocket, clipped to clothing, or attached directly to the skin with an adhesive sleeve.
How the Tandem Mobi Delivers Insulin
The Mobi holds up to 200 units of rapid-acting insulin (such as Humalog, NovoLog, Admelog, or Fiasp) in a prefilled cartridge. Insulin flows through a short tubing set into an infusion site on the skin, typically changed every 2 to 3 days.
The pump delivers a steady background infusion (basal rate) and additional doses (boluses) at meals or to correct high glucose. Basal rates can be programmed for different times of day, and bolus amounts are calculated using settings for insulin-to-carb ratio and correction factor.
Control-IQ Technology
The Mobi pairs with a Dexcom G6 or G7 continuous glucose monitor to enable Control-IQ, Tandem’s automated insulin delivery algorithm. Every 5 minutes, Control-IQ analyzes CGM data and predicts glucose 30 minutes ahead. Based on that prediction, the pump can:
- Increase basal delivery if glucose is projected to rise above 160 mg/dL
- Decrease basal delivery if glucose is projected to fall below 112.5 mg/dL
- Suspend basal delivery if glucose is projected to drop below 70 mg/dL
- Deliver automatic correction boluses when glucose is predicted above 180 mg/dL
A 2019 New England Journal of Medicine trial of Control-IQ technology showed that users spent significantly more time in the target range (70-180 mg/dL) compared to sensor-augmented pump therapy without automation.
Who Tandem Mobi Is For
The Tandem Mobi is FDA-cleared for adults and children 6 years and older with type 1 diabetes who use rapid-acting insulin. It can also be used in people with type 2 diabetes who are on insulin therapy and meet clinical criteria. According to the American Diabetes Association, automated insulin delivery systems are recommended for people with type 1 diabetes who can use the technology safely.
Insulin pumps are not used for prediabetes or for most people with type 2 diabetes who are not on insulin. If you are exploring treatment options for elevated blood sugar and your A1C falls in the prediabetes range, lifestyle changes and oral medications are the typical starting point rather than pump therapy.
Setup and Daily Use
Setting up the Mobi involves filling the cartridge with insulin, priming the tubing, placing the infusion site, and connecting the pump. The iPhone app is used for programming settings, delivering boluses, and reviewing history. A small button on the pump itself allows for manual bolus delivery if your phone is unavailable.
Infusion sites are typically placed on the abdomen, upper arm, thigh, or back of the hip. Sites should be rotated every 2 to 3 days to prevent site reactions and insulin absorption problems.
| Specification | Details |
|---|---|
| Size | ~2 x 1.5 x 0.6 inches |
| Weight | ~1 ounce |
| Reservoir capacity | 200 units |
| Battery | Rechargeable, 3-5 days |
| Water resistance | IP28 (8 feet for 60 minutes) |
| CGM integration | Dexcom G6 and G7 |
| Control method | iPhone app + manual bolus button |
Benefits of the Tandem Mobi
The Mobi offers several advantages over older or larger pumps:
- Discreet size — Easy to wear under clothing or during exercise.
- Wireless charging — Uses standard Qi charging pads without plugging in cables.
- Smartphone control — Most functions handled through a familiar iPhone interface.
- Automated insulin delivery — Control-IQ helps reduce both high and low blood sugar episodes.
- Water resistance — Can be worn during showers, swimming, and light water exposure.
Common Challenges
Like any insulin pump, the Mobi has some practical challenges users should be aware of:
- Smartphone dependency — If your phone battery dies or is unavailable, you rely on the manual bolus button.
- Infusion site adhesion — Sweat, friction, and active lifestyles can affect adhesion.
- Tubing kinks — Though short, the tubing can still kink or disconnect.
- Occasional pairing issues — Bluetooth connection between phone and pump can occasionally drop.
- Cost — Pumps and supplies can be expensive, especially without good insurance coverage.
Insurance and Cost
The Tandem Mobi is typically covered by commercial insurance, Medicare, and Medicaid for people with type 1 diabetes meeting clinical criteria. Out-of-pocket costs vary widely depending on plan, deductible, and durable medical equipment coverage. The pump itself can cost 4,000 to 6,000 dollars without insurance, plus ongoing costs for infusion sets and cartridges.
Tandem offers financial assistance programs and payment plans for eligible patients. Check with your healthcare provider and insurance plan to understand coverage before committing.
The Bottom Line
The Tandem Mobi may help people with type 1 diabetes who value discretion, automation, and smartphone control of their insulin delivery. With Control-IQ technology and Dexcom CGM integration, it delivers automated insulin adjustments that have been shown to improve time in range and reduce hypoglycemia. If you are considering the Mobi, talk with your diabetes care team about whether its size, features, and smartphone-based interface match your lifestyle and needs.
