Tandem Diabetes Care now offers two insulin pumps powered by the same Control-IQ technology: the established t:slim X2 and the newer, smaller Tandem Mobi. Both deliver automated insulin delivery with CGM integration and real-world clinical evidence behind the algorithm. What differs is how they look, how they're controlled, how they're worn, and what trade-offs come with each approach. If you're trying to decide between them, this guide lays out everything you need to know.
t:slim X2 vs. Tandem Mobi: Side-by-Side
According to the ADA Consumer Guide and Tandem Mobi Consumer Guide listings, here is how the two systems compare on the features most users care about:
| Feature | Tandem t:slim X2 with Control-IQ | Tandem Mobi with Control-IQ |
|---|---|---|
| Size | 3.13 x 2.0 x 0.6 in. (3.95 oz.) | Less than half the size of t:slim X2 (1.06 oz.) |
| Insulin Capacity | 300-unit reservoir (3mL) | 200-unit cartridge |
| On-Device Screen | Yes (3.7 in. high-contrast color touchscreen) | No (single bolus button only) |
| Primary Control | On-pump touchscreen (app optional) | Smartphone app required (iOS; Android coming 2026) |
| Bolus Without Phone | Yes (via touchscreen) | Yes (via on-pump button; limited to single bolus) |
| Compatible CGMs | Dexcom G6, Dexcom G7, FreeStyle Libre 2/3 Plus | Dexcom G6, Dexcom G7 |
| AID Algorithm | Control-IQ (predicts glucose 30 min ahead) | Control-IQ (same algorithm) |
| Wear Options | Clip, pocket, holster | Coin pocket, clothing clip, or on-body adhesive sleeve |
| Water Resistance | Watertight up to 3 ft for 30 minutes | Watertight up to 3 ft for 30 minutes |
| Charging | Micro-USB; lasts 5 to 7 days per charge | Wireless charging |
| Software Updates | Remote software updates available | Remote software updates available |
| Approved Ages | Type 1: ages 2+; Type 2: adults 18+ | Ages 6+ |
| Exclusive Tubing Option | Standard Tandem infusion sets | Standard Tandem sets plus exclusive 5-inch tubing option |
Tandem t:slim X2 with Control-IQ: The Full-Featured Touchscreen Option
The Tandem t:slim X2 with Control-IQ is a slim, touchscreen pump that has been in wide clinical use since Control-IQ technology received FDA clearance in late 2019. It carries one of the largest evidence bases of any AID system available, with real-world studies consistently demonstrating improved time in range and reduced hypoglycemia compared to sensor-augmented pumping.
The t:slim X2's 3.7-inch high-contrast color touchscreen allows full pump management directly from the device, including bolus programming, basal rate adjustment, CGM data viewing, and system settings, without needing a smartphone. This is a meaningful advantage for users who prefer not to rely on their phone for pump interactions, particularly during activities, in work environments where phone use is inconvenient, or in situations where battery life is a concern.
The 300-unit reservoir gives the t:slim X2 a capacity advantage over the Mobi, which is relevant for users with higher total daily insulin requirements. The t:slim X2 also supports the widest CGM compatibility of any Tandem pump, working with Dexcom G6, Dexcom G7, and both the FreeStyle Libre 2 Plus and FreeStyle Libre 3 Plus. If you currently use an Abbott CGM and want to keep it while moving to a Tandem pump, the t:slim X2 is the only Tandem option that currently supports it.
Infusion set compatibility for the t:slim X2 includes the full range of Tandem-branded sets, including the AutoSoft XC and Extended infusion set. The pump charges via micro-USB and typically lasts five to seven days per full charge.
Tandem Mobi with Control-IQ: The World's Smallest Durable AID System
The Tandem Mobi with Control-IQ is less than half the size of the t:slim X2 and, at the time of its FDA clearance, was described as the world's smallest durable automated insulin delivery system. It fits in a coin pocket, clips discreetly to clothing, or can be worn directly on the body using an adhesive sleeve sold separately, making it one of the most versatile wear options of any tubed pump currently available.
Unlike the t:slim X2, the Mobi has no touchscreen. A single on-pump button allows you to deliver a bolus without your phone, but all other pump management, including basal rate changes, CGM viewing, settings adjustments, and activity mode, is handled through the Tandem Mobi app on a compatible iOS device. Android compatibility received FDA approval in 2025 and is expected to launch in 2026. This makes the Mobi the only AID system currently fully controllable via a mobile app, which is a selling point for users who are comfortable managing everything from their phone and prefer the smallest possible wearable footprint.
The Mobi uses wireless charging rather than a USB cable, which some users find more convenient for daily top-ups. Its 200-unit insulin cartridge is smaller than the t:slim X2 reservoir, which may require more frequent fills for users with higher insulin needs. CGM compatibility is currently limited to Dexcom G6 and Dexcom G7; FreeStyle Libre integration is not yet available for the Mobi.
One exclusive feature of the Mobi is a 5-inch tubing option, the shortest available for any Tandem pump. This ultra-short tubing is designed specifically for on-body or close-carry wear, keeping the connection between the pump and infusion site tight and discreet. Available infusion set options compatible with the Mobi include the Tandem Mobi TruSteel kit and the standard Tandem-branded soft cannula sets.
The Right Tandem Pump Depends on How You Live
Both pumps run the same proven Control-IQ algorithm and will deliver similar clinical outcomes for most users. The decision is almost entirely a lifestyle and preference question. If you want on-device control, higher insulin capacity, and the broadest CGM compatibility, the t:slim X2 is the clearer choice. If you want the smallest footprint possible, full smartphone control, wireless charging, and maximum discretion, the Mobi is built for you. If you currently use an Abbott FreeStyle Libre CGM, that's currently a deciding factor in favor of the t:slim X2 until Mobi expands its CGM compatibility. Explore our Learning Center and Education page for more guides on Tandem products and automated insulin delivery.
Frequently Asked Questions About Tandem t:slim X2 vs. Tandem Mobi
Can I switch between the t:slim X2 and Tandem Mobi if I change my mind?
Switching pumps typically requires a new prescription and insurance re-verification, as each pump is a distinct device with its own prior authorization process. Tandem offered a technology access program for existing t:slim X2 customers to transition to the Mobi at a reduced cost when the Mobi first launched. Check with your provider and supplier about current upgrade pathways. The infusion set supplies are compatible across both Tandem systems, so your existing infusion set inventory would transfer.
What happens if my phone dies while using the Tandem Mobi?
The Mobi continues delivering your programmed basal insulin automatically in automated mode even when your phone is unavailable or out of range. The single on-pump button allows you to deliver a standard bolus without the app. For access to settings, CGM data, bolus calculators, and advanced features, you will need a charged, compatible phone. Keeping your phone charged and carrying a backup battery pack is a practical precaution for Mobi users who rely entirely on app control.
Does the Tandem Mobi work with the FreeStyle Libre sensors?
As of the time of this writing, the Tandem Mobi is compatible only with Dexcom G6 and Dexcom G7 CGMs. FreeStyle Libre 2 Plus and Libre 3 Plus integration is available on the t:slim X2 but not currently on the Mobi. If you use an Abbott CGM and are considering a Tandem pump, the t:slim X2 is the appropriate choice at this time. CGM compatibility for the Mobi may expand in the future as Tandem continues software development.
Which pump is better for higher insulin doses?
The t:slim X2 has a 300-unit reservoir compared to the Mobi's 200-unit cartridge. For users with total daily insulin needs above roughly 80 to 90 units, the larger reservoir means fewer cartridge changes per week with the t:slim X2. The Mobi's smaller capacity means more frequent fills for high-dose users, which is worth factoring into your decision. If you're unsure about your typical insulin needs relative to the reservoir size, your diabetes care team can help you estimate based on your current total daily dose.
Are the infusion sets the same for both pumps?
Most Tandem-branded infusion sets are compatible with both pumps, including the AutoSoft XC and the TruSteel options. The Tandem Mobi also offers an exclusive 5-inch tubing length designed for close-body or on-body wear, which is not available for the t:slim X2. Regardless of which pump you use, all Tandem infusion sets use the t:lock connector, which is specific to Tandem pumps and not interchangeable with other brands.
Order Your Tandem Pump Supplies Through Adapt Health Diabetes
Adapt Health Diabetes carries supplies for both Tandem pump systems, including infusion sets, cartridges, and compatible CGM sensors, verified through your insurance and delivered to your door. Browse our full Tandem Diabetes collection, or visit our Resources page for more information. Questions about coverage or which pump to choose? Contact our team and we'll help.
This article is for educational purposes only and does not replace professional medical advice. Always consult your healthcare provider regarding insulin pump selection and diabetes management decisions.
Sources
- American Diabetes Association. t:slim X2 Insulin Pump With Control-IQ. ADA Consumer Guide.
- American Diabetes Association. Tandem Mobi System. ADA Consumer Guide.
- American Association of Diabetes Care and Education Specialists. Tandem Mobi FDA Approved. danatech by ADCES. 2023.
