Tandem Mobi (pump)

The Tandem Mobi is, by the manufacturer's claim, the world's smallest durable automated insulin delivery system — a miniature pump less than half the size of Tandem's own t:slim X2, small enough to slip into the coin pocket of a pair of jeans.¹² It is a tubed pump, not a patch, but it shrinks the tubed format dramatically: the small durable pump body connects to the body through a short, detachable infusion set, including a 5-inch tubing option made specifically for the Mobi, so you can briefly disconnect to shower or swim.²

Reservoir and wear. The Mobi uses a clear ~200-unit insulin cartridge, smaller than the t:slim X2's ~300-unit cartridge, which is the trade-off for its size.¹² The cartridge is paired with standard Tandem infusion sets, so the site/cannula is changed every two to three days like any conventional pump.² The pump body itself is durable and rechargeable by wireless (inductive) charging, and it is water-resistant to an IP28 rating (tested at 8 feet for 2 hours).³

Infusion set and occlusion detection. Because it is compatible with the full Tandem infusion-set range, users can mix and match cannula type, angle, and tubing length.²³ Like other Tandem pumps it includes occlusion (blockage) detection and alarms; as with any infusion-set pump, a kinked or bent cannula will not always trigger an alarm, so site rotation and monitoring still matter.⁴

Recall — "Malfunction 12". The Mobi carries an FDA Class 1 recall (recall number Z-0427-2026, the FDA's most serious category, covering 17,745 units in commerce). A software-design fault could make the pump falsely detect a vibration-motor failure and raise "Malfunction 12": the pump then cannot operate, insulin delivery and any active CGM session stop, and the phone app can no longer receive data from the pump — which can lead to hyperglycemia and, untreated, to DKA.⁵ Only software versions 7.6.0.1, 7.6.0.3 and 7.7.0.1 are affected; for this Malfunction 12 issue specifically, an update to 7.9.0.2 or later is the fix. It does not resolve every other open Mobi correction. This is a correction, not a removal — the pumps stay on the market. Per the FDA, as of 4 November 2025 Tandem had reported four serious injuries and no deaths.⁵

Two other open software corrections have different actions. Class I Z-1520-2025 covers 85 Mobi pumps on Control-IQ+ software 7.9: faulty interpolation around a CGM data gap when the estimated glucose value exceeds 255 mg/dL can under- or over-deliver insulin, and the FDA-listed action says affected users should turn off Control-IQ+.⁶ Shared Class II Z-0232-2026 covers Mobi 7.9.0.1 (and named t:slim X2 versions) paired with Dexcom G7: starting a new sensor session too soon can trigger an unexpected automatic correction bolus and hypoglycemia, so affected users must follow Tandem's sensor-pairing timing instructions until the correction is installed.⁷ Exact software and configuration determine which notice applies.

Which CGMs and algorithms it works with. The Mobi is a closed commercial AID system. It integrates in the US with Dexcom G6, standard G7 and, since Q2 2026, G7 15 Day, and runs Tandem's Control-IQ+ algorithm, which reads CGM values, predicts glucose 30 minutes ahead, and automatically adjusts insulin every five minutes.³⁸⁹ It does not support Abbott's FreeStyle Libre on the Mobi, and it is not an open platform — there is no official DIY/open-source looping.¹⁰ The underlying Control-IQ algorithm is among the best-evidenced in the field: in the pivotal NEJM randomized trial it raised time in range from 61% to 71% versus an unchanged control group.¹¹ Real-world data from more than 40,000 Control-IQ+ users (t:slim X2 and Mobi) show a median time in range around 71% with very low hypoglycemia.¹² Tandem cites up to 79% daytime and 90% overnight time in range.¹

Phone bolusing. The Mobi is fully controllable from a compatible phone — you can bolus for meals directly from the app.³ iOS control launched at U.S. release in February 2024, and the FDA cleared the Android app on 10 November 2025 (Pixel 6-10, Galaxy S21-S25), with broad rollout in early 2026.²¹ A multifunction button on the pump delivers a bolus without the phone as a backup.²

Pregnancy indication. On 27 April 2026 the FDA cleared Control-IQ+ on both Mobi and t:slim X2 for pregnancy complicated by type 1 diabetes; Tandem announced the corresponding European CE-mark expansion on 5 June.¹³¹⁴ The randomized CIRCUIT evidence behind that label tested Control-IQ on t:slim X2 hardware, so it supports the shared algorithm and pregnancy indication rather than a Mobi-specific hardware trial.

Access and cost. The Mobi is established in the United States for people aged 2 and older.³ Tandem reported on 6 August 2026 that an international commercial rollout had begun during Q2, but its filing did not identify the first countries or support a claim of blanket availability across Europe, Canada or Australia.⁹ In the US it is distributed through durable-medical-equipment channels; exact out-of-pocket cost depends on insurance.

What's coming. Tandem is developing a tubeless version of the Mobi: the same pump body would slide into an adhesive patch (via a side-clip design) using a new 7-day SteadiSet infusion set, making it a first-of-its-kind hybrid that can be worn either tubed or tubeless.¹⁵ The company confirmed that it submitted the 510(k) in Q2 2026.⁹ Submission is not FDA clearance, so today Mobi remains a tubed pump and no launch date is assured.

References

1. Beyond Type 1. Tandem Mobi Receives FDA Clearance for Use with Android Smartphones. beyondtype1.org (2025). https://beyondtype1.org/fda-approval-tandem-mobi-android/ ↩ ↩² ↩³ ↩⁴

2. Beyond Type 1. The Tandem Mobi is Now Available. beyondtype1.org (2024). https://beyondtype1.org/the-tandem-mobi-is-now-available/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷

3. Tandem Diabetes Care. Tandem Mobi Automated Insulin Delivery System. tandemdiabetes.com (accessed 2026). https://www.tandemdiabetes.com/products/insulin-pumps/tandem-mobi ↩ ↩² ↩³ ↩⁴ ↩⁵

4. Sawyer A, Forlenza GP, Wadwa RP. An overview of the t:slim X2 and Mobi insulin pumps with Control-IQ technology: patient safety and device efficacy. Expert Review of Medical Devices (2025). doi:10.1080/17434440.2025.2585061. https://pubmed.ncbi.nlm.nih.gov/41175172/ ↩

5. U.S. Food and Drug Administration. Class 1 Device Recall: Tandem Mobi Insulin Pump with Interoperable Technology (recall Z-0427-2026; initiated 6 October 2025, posted 5 November 2025). accessdata.fda.gov (2025). https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfres/res.cfm?id=216259 ↩ ↩²

6. U.S. FDA. Class I Device Recall Tandem Mobi Control-IQ+ software 7.9 — Z-1520-2025 (open; 85 units; under-/over-delivery risk around CGM data gaps). https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfres/res.cfm?id=212817 ↩

7. U.S. FDA. Class II Device Recall Tandem Mobi/t:slim X2 with Dexcom G7 — Z-0232-2026 (open; unexpected autobolus risk on named versions; follow sensor-pairing timing instructions). https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfres/res.cfm?id=215511 ↩

8. Beyond Type 1. Tandem Mobi Pump and the Dexcom G7 CGM Are Now Connected. beyondtype1.org (2024). https://beyondtype1.org/tandem-mobi-dexcom-g7-integration/ ↩

9. Tandem Diabetes Care. Second Quarter 2026 Financial Results (US G7 15 Day compatibility; submitted tubeless-capability 510(k); international commercial rollout began). SEC Exhibit 99.1, 6 August 2026. https://www.sec.gov/Archives/edgar/data/1438133/000143813326000124/ex991-q2earningsrelease2026.htm ↩ ↩² ↩³

10. Tandem Diabetes Care. CGM Sensor Compatibility. tandemdiabetes.com (accessed 2026). https://www.tandemdiabetes.com/support/cgm-compatibility ↩

11. Brown SA, Kovatchev BP, Raghinaru D, et al. Six-Month Randomized, Multicenter Trial of Closed-Loop Control in Type 1 Diabetes. New England Journal of Medicine (2019). doi:10.1056/NEJMoa1907863. https://pubmed.ncbi.nlm.nih.gov/31618560/ ↩

12. Assadi KZ, D'Souza EW, Pinsker JE, Messer LH. First Use of Control-IQ+ Technology in Newly Indicated Populations. Diabetes Technology & Therapeutics (2026). doi:10.1177/15209156261456818. https://pubmed.ncbi.nlm.nih.gov/42267588/ ↩

13. Tandem Diabetes Care. Control-IQ+ automated insulin delivery technology now FDA cleared for pregnancy in type 1 diabetes (27 April 2026; applies to t:slim X2 and Mobi). https://investor.tandemdiabetes.com/news-releases/news-release-details/tandem-diabetes-cares-control-iq-automated-insulin-delivery ↩

14. Tandem Diabetes Care. Automated insulin delivery systems receive CE mark for type 2 diabetes and type 1 diabetes during pregnancy (5 June 2026; applies to t:slim X2 and Mobi). https://investor.tandemdiabetes.com/news-releases/news-release-details/tandem-diabetes-care-automated-insulin-delivery-systems-receive ↩

15. Reuter E. Tandem to file tubeless insulin pump with FDA this quarter. MedTech Dive (2025). https://www.medtechdive.com/news/tandem-to-file-tubeless-insulin-pump-with-fda-this-quarter/819722/ ↩