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Tandem Control-IQ

Tandem Diabetes Care

A mature hybrid closed-loop system pairing the t:slim X2 (or Tandem Mobi) pump with Dexcom CGMs. It automatically adjusts basal insulin every 5 minutes and delivers automatic correction boluses, with dedicated sleep and exercise targets. One of the most-studied automated insulin delivery systems, backed by pivotal randomized trials in adults and children plus large real-world datasets.

Available nowStrong evidencehybrid-closed-looptubedphone-controlOfficial site ↗

The scorecard

Time in range76

Achieved ~71% time-in-range in the DCLP3 pivotal T1D RCT (n=112 adults/adolescents, up from 61%), and 64% TIR in a real-world pediatric T1D cohort (n=114); real-world Medicare reached 74% but blends T1D+T2D, so ~71% anchors the score near the 780G benchmark.[1]

Hypo protection78

Achieved time-below-70 of ~1.6% in DCLP3 and ~1% in the real-world Medicare T1D cohort (2.7% time <3.9 mmol/L in pediatric real-world), with no severe hypoglycemia in the pivotal RCT — strong predictive low-suspend protection.[1]

Automation level66

Automates basal and auto-corrections (up to once/hour), but remains hybrid — still requires carb counting and announced meals.

Average glucose74

Achieved GMI 7.0% in the real-world Medicare T1D cohort (HbA1c ~7.1-7.4% across pivotal and pediatric real-world data), tracking a few points below the time-in-range score.[2]

Low variability72

Achieved ~71% T1D time-in-range with frequent 5-minute basal adjustments and auto-corrections holds glucose CV in the typical good-hybrid-loop range (~27-34%), though large unannounced meals still drive swings.[1]

Exercise handling68

Manual Exercise mode raises the target to 140-160 mg/dL to blunt activity lows, but must be switched on by the user.

Customizability74

Adjustable basal/ratio/sensitivity profiles plus Sleep and Exercise activity modes; Control-IQ+ adds an optional lower treatment range.

Access & cost64

Broadly available across the US, UK, EU, Canada and Australia via DME/prescription channels; cost and coverage still vary by region.

Freedom (form factor)48

Runs on the tubed t:slim X2 — a slim pump, but with tubing and a separate body to carry and disconnect.

Glycemic criteria are scored on the levels actually achieved in large real-world Type 1 diabetes cohorts — not the headline improvement over a trial's baseline (an improvement that looks bigger when the starting population was doing poorly). Type 2 diabetes trial data is never used to score a Type 1 system; where only improvement data exists, it informs the rationale, not the score. Freedom captures form factor and wearability, so a tubeless system is rewarded for the mobility a tubed one can't match.

The full picture

Control-IQ is Tandem Diabetes Care's hybrid closed-loop ("artificial pancreas") system and the most-studied automation benchmark in Type 1 diabetes today. Three parts work together: the t:slim X2 pump (or the smaller Tandem Mobi), a Dexcom CGM (originally G6, now also G7), and the Control-IQ algorithm, which predicts glucose 30 minutes ahead and adjusts insulin every 5 minutes.12

How the automation works. Within a standard target of 112.5-160 mg/dL, the algorithm raises or lowers basal insulin based on the prediction, and delivers an automatic correction bolus (60% of the calculated dose, no more than once per hour) when glucose is heading above 180 mg/dL.1 A Sleep mode tightens the overnight target (112.5-120 mg/dL) and an Exercise mode raises it (140-160 mg/dL) to guard against activity lows — both set manually.1 It stays "hybrid": you still count carbs and announce meals, because the system handles the background well but cannot fully absorb a surprise meal.1

Pivotal trial results. In the 6-month adult/adolescent DCLP3 randomized trial (168 people, ages 14-71), time in range (70-180 mg/dL) rose from 61% to 71% with Control-IQ versus 59% in the control group, time below 70 mg/dL fell, HbA1c dropped 0.33 percentage points, and the system was in closed-loop mode 90% of the time — with no severe hypoglycemia.2 In the 16-week pediatric DCLP5 trial (101 children ages 6-13), time in range improved from 53% to 67% versus 51% to 55% in controls, with closed-loop active 93% of the time and no diabetic ketoacidosis or severe lows.3 When trial participants were switched off closed-loop back to predictive low-glucose suspend, their time in range and HbA1c drifted back toward pre-Control-IQ levels — direct evidence the algorithm itself drives the benefit.4

Real-world confirmation. In over 5,000 Medicare and Medicaid users, starting Control-IQ raised time in range (Medicare 64% to 74%) and lowered GMI (7.3% to 7.0%), matching trial-level results in everyday use.5

Ages, indications and access. Control-IQ (now branded Control-IQ+) is FDA-cleared for Type 1 diabetes from age 2 and up, and as of February 2025 for Type 2 diabetes in adults 18+ based on a pivotal trial in over 300 people.67 It first cleared in December 2019 (ages 14+), expanded to ages 6+ in June 2020, and is widely available across the US, UK, EU, Canada and Australia.86 A modified-range crossover trial (ages 3-57) confirmed an optional lower treatment range (90-130 mg/dL) safely nudged time in range higher across every age group.9

What's coming. Control-IQ+ now integrates with the smaller Dexcom G7 and runs on the discreet Tandem Mobi pump.10 In April 2026 the FDA cleared Control-IQ+ for use during pregnancy in Type 1 diabetes — the first AID system with a pregnancy indication.11 The persistent ceiling remains the "hybrid" requirement to announce meals; Tandem's lower-range and late-bolus features are incremental steps toward absorbing unannounced meals automatically.9

References

  1. Beato-Víbora PI, et al. The Hybrid Closed-Loop System Tandem t:slim X2 with Control-IQ Technology: Expert Recommendations. J Diabetes Sci Technol / PMC (2024). https://pmc.ncbi.nlm.nih.gov/articles/PMC10786785/ ↩ ↩2 ↩3 ↩4

  2. Brown SA, et al. Six-Month Randomized, Multicenter Trial of Closed-Loop Control in Type 1 Diabetes. N Engl J Med (2019). https://doi.org/10.1056/NEJMoa1907863 ↩ ↩2

  3. Breton MD, et al. A Randomized Trial of Closed-Loop Control in Children with Type 1 Diabetes. N Engl J Med (2020). https://doi.org/10.1056/NEJMoa2004736 ↩

  4. Brown SA, et al. Glycemic Outcomes of Use of CLC Versus PLGS in Type 1 Diabetes: A Randomized Controlled Trial. Diabetes Care (2020). https://doi.org/10.2337/dc20-0124 ↩

  5. Forlenza GP, et al. Real-World Evidence Supporting Tandem Control-IQ Hybrid Closed-Loop Success in the Medicare and Medicaid Type 1 and Type 2 Diabetes Populations. Diabetes Technol Ther (2022). https://doi.org/10.1089/dia.2022.0206 ↩

  6. Dexcom. Control-IQ+ Technology integrates with Dexcom G7 (indications: Type 1 ages 2+, Type 2 ages 18+). Dexcom (2025). https://www.dexcom.com/en-us/all-access/dexcom-cgm-explained/tandem-control-iq-dexcom-g7 ↩ ↩2

  7. Pharmacy Times. Automated Insulin Delivery Technology Receives FDA Clearance for Individuals With Type 2 Diabetes. Pharmacy Times (2025). https://www.pharmacytimes.com/view/automated-insulin-delivery-technology-receives-fda-clearance-for-individuals-with-type-2-diabetes ↩

  8. Breakthrough T1D. Tandem Control-IQ — Now Authorized For Children (FDA cleared Dec 13, 2019; expanded to ages 6+ June 17, 2020). Breakthrough T1D (2020). https://www.breakthrought1d.org/news-and-updates/tandem-control-iq-now-authorized-for-children/ ↩

  9. Brown SA, et al. Randomized, Crossover Trial of Control-IQ Technology with a Lower Treatment Range and Modified Meal Bolus Module. Diabetes Technol Ther (2024). https://doi.org/10.1089/dia.2024.0501 ↩ ↩2

  10. diaTribe. Tandem Control-IQ+: How It Works, Features, and Latest Updates (Dexcom G6/G7; t:slim X2 and Tandem Mobi). diaTribe (2025). https://diatribe.org/diabetes-technology/tandems-control-iq-cleared-united-states ↩

  11. Tandem Diabetes Care. Control-IQ+ Automated Insulin Delivery Technology Now FDA Cleared for Pregnancy in Type 1 Diabetes. BusinessWire (2026). https://www.businesswire.com/news/home/20260427815489/en/Tandem-Diabetes-Cares-Control-IQ-Automated-Insulin-Delivery-Technology-Now-FDA-Cleared-for-Pregnancy-in-Type-1-Diabetes ↩

What's next for this

  • →Control-IQ+ integrates with the smaller Dexcom G7 and runs on the Tandem Mobi pump
  • →FDA clearance of Control-IQ+ for use during pregnancy in type 1 diabetes · April 2026
  • →Lower-range and late-bolus features as incremental steps toward automatically absorbing unannounced meals

Sources

  1. [1]Six-Month Randomized, Multicenter Trial of Closed-Loop Control in Type 1 Diabetes (DCLP3, NCT03563313) · peer-reviewed · 2019-10-31
  2. [2]Real-World Evidence Supporting Tandem Control-IQ Hybrid Closed-Loop Success in the Medicare and Medicaid Type 1 and Type 2 Diabetes Populations · peer-reviewed · 2022-07-26
  3. [3]Real-World Glycemic and Person-Reported Outcomes After Tandem Control-IQ Initiation in Children With Type 1 Diabetes · peer-reviewed · 2025-11-18