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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

Does the benefit last? The best answer so far comes from OB2F, the French nationwide observatory of 2,741 people starting an automated insulin delivery system (systems generally, not Control-IQ alone). Median time in range was 70.0% at 12 months and still 70.0% at 24 months — statistically non-inferior, i.e. the gain does not fade — about 12 points above where people started, with HbA1c falling from 7.6% to 7.1%, fewer severe hypoglycemia episodes, and only 2.1% of people stopping the therapy.6 A separate nationwide Belgian audit points the same way: adults on a hybrid closed loop recorded HbA1c 7.0%, time in range 73% and time below range 1.5% — better than any other treatment modality in the country.7 Neither study isolates Control-IQ from its competitors, so read them as evidence that mainstream hybrid closed-loop results hold up over years, rather than as a head-to-head verdict.

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.89 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.108 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.11

What's coming. Control-IQ+ now integrates with the smaller Dexcom G7 and runs on the discreet Tandem Mobi pump.12 In April 2026 the FDA cleared Control-IQ+ for use during pregnancy in Type 1 diabetes — the first AID system cleared for pregnancy in the US (in Europe, CamAPS FX has carried a pregnancy indication for years).13 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.11

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. Julla JB, et al. Sustained Follow-up of Automated Insulin Delivery in a Real-World Setting: Results at 2 Years of the French Nationwide Observatory OB2F. Diabetes Technol Ther (2026). https://doi.org/10.1177/15209156261465478 ↩

  7. Lavens A, et al. Impact of Technology Introduction on Glycemic Control of People Living with Type 1 Diabetes in Belgium: An Observational, Real-World Study. Diabetes Technol Ther (2026). https://doi.org/10.1177/15209156261464233 ↩

  8. 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

  9. 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 ↩

  10. 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/ ↩

  11. 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

  12. 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 ↩

  13. 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
  4. [4]Sustained Follow-up of Automated Insulin Delivery in a Real-World Setting: Results at 2 Years of the French Nationwide Observatory OB2F · peer-reviewed · 2026-07-10 — 2,741 people starting AID; median time-in-range 70.0% at both 12 and 24 months (non-inferior), HbA1c 7.6% to 7.1%, 2.1% discontinuation. Covers AID systems generally, not Control-IQ specifically.
  5. [5]Impact of Technology Introduction on Glycemic Control of People Living with Type 1 Diabetes in Belgium: An Observational, Real-World Study · peer-reviewed · 2026-07-02 — Nationwide audit — adults on hybrid closed-loop reached HbA1c 7.0%, time-in-range 73%, time-below-range 1.5%: the best of any modality recorded.