Research Studies

1. Patients with a diagnosis of Type 2 diabetes (T2D) mellitus who, in the opinion of their clinician and/or the study investigator, are likely to benefit (i.e., have improved glycemic outcomes) from the introduction of basal insulin, specifically Glargine U-100, to their diabetes therapy regimen. 2. Ages ≥ 18 years (“age” determined at the time of the Screening Visit) 3. A1c > 7.5% 4. Bodyweight between 40-200 kg 5. Comfortable with and willing to administer basal insulin injections, once a day, for up to 50 consecutive days, and log daily injections in the Dexcom CGM mobile application.

Inclusion Criteria Subjects may be included if they meet all of the following criteria: 1. Patients with a diagnosis of Type 2 diabetes (T2D) mellitus who, in the opinion of their clinician and/or the study investigator, are likely to benefit (i.e., have improved glycemic outcomes) from the introduction of basal insulin, specifically Glargine U-100, to their diabetes therapy regimen. 2. Ages ≥ 18 years (“age” determined at the time of the Screening Visit) 3. A1c > 7.5% 4. Bodyweight between 40-200 kg 5. Comfortable with and willing to administer basal insulin injections, once a day, for up to 50 consecutive days, and log daily injections in the Dexcom CGM mobile application. 6. Possess a smartphone capable of running the commercially available US Dexcom G6 CGM and the mobile application and willingness to use smartphone and Dexcom CGM for the duration of the study 7. Subject is able to speak, read, and write English 8. Willing to complete questionnaires and interviews during the study 9. Willing to wear Dexcom CGM for duration of study, collecting a minimum of 90% CGM data in the Dexcom CGM mobile application 10. Willing to conduct three at-home self-monitoring blood glucose (SMBG) measurements, one per day, during Phase 4 of the study 11. Primary residence within +/- 1 time-zone hour of the study clinic. Exclusion Criteria Subjects will be excluded if they meet any of the following criteria: 1. Recent severe hypoglycemia, complicated by seizure(s) or loss of consciousness, in the past 3 months 2. Subjects with any contraindications for starting basal insulin therapy 3. Glomerular filtration rate (eGFR) < 45 ml/min/1.73m2 4. Continuing use of sulfonylureas or other drugs that can severely increase the risk of hypoglycemia when using with insulin 5. Titrating other medications simultaneously 6. Any condition that, in the opinion of the Investigator, would interfere with a subject’s participation in the trial or pose excessive risk to subject and/or study staff 7. For subjects of child-bearing potential: Pregnancy, demonstrated by a positive test no more than 72 hours prior to Clinic Visit 1, and not willing to use an acceptable form of contraception during system use. Also, postpartum subjects currently breastfeeding (defined as: baby to breast, bottle feeding mother’s expressed breast milk, or donating mother’s expressed breast milk) 8. Has used insulin (basal or prandial) in the last 30 days 9. A pattern of life in which the subject is not generally asleep during the hours of 12am (midnight) and 5am. 10. Current participation in another investigational study protocol (If a subject has recently completed participation in a drug study, the subject must have completed that study at least 30 days prior to being enrolled in this study). Note: Subjects will not be excluded if enrolled in another observational trial, wherein the subject is in the follow-up phase and no tests/procedures impacting the subject’s health are required. Subjects will be excluded if they have been previously enrolled in the same study session. 11. The subject, immediate family member(s), and/or person(s) living within the household work for Dexcom, Medtronic, Glysens Inc., Abbott Laboratories, Roche, Senseonics, Waveform, Ascensia Diabetes Care, or POCTech. 12. Required or scheduled to have a Magnetic Resonance Imaging (MRI) scan or diathermy during system use. 13. Presence of extensive skin changes/diseases at sensor wear site(s) that preclude wearing the sensor(s) on skin (e.g., extensive psoriasis, recent burns or severe sunburn, extensive eczema, extensive scarring, extensive tattoos, or dermatitis herpetiformis) 14. The subject plans to travel beyond +/- 1 time-zone hour from the study clinic for 7+ consecutive days during the Phase 3 period