Inclusion Criteria:  Age 18-85 years, BMI ≥ 18.5, have had clinical type 1 diabetes for at least one year, and have taken insulin for at least 1 year  Prescription diabetes medication regimen stable for > 1 month, including any adjunctive anti-diabetic medications (except for medications that will not affect the safety of the study and are not expected to affect any outcome of the study, in the judgment of the site principal investigator) This does not include changes to any insulin doses, including basal rates/long-acting insulin doses, carbohydrate to insulin ratios and correction factors Willing to wear one Dexcom CGM transmitter and sensor (sensor must be changed every 10 days), and one infusion set that must be replaced at least every 3 days. Endocrinology practice criterion is that diabetes is managed using sensor-augmented insulin pump therapy or artificial pancreas therapy for ≥ 3 months) Primary care practice criteria are that diabetes is managed by multiple daily insulin injections (insulin-pump naïve). TH group criterion is that participant must have hardware and internet access capable of 2-way video and audio communication  Exclusion Criteria:  Unable to provide informed consent (e.g. impaired cognition or judgment) Unable to safely comply with study procedures and reporting requirements (e.g. impairment of vision or dexterity that prevents safe operation of the bionic pancreas, impaired memory) Unable to speak and read English, as iLet BP support materials and device menus are currently available in English only.  Plan to change usual diabetes regimen in the next 2 months including before and during participation in the study  This would include changing from MDI to pump or from pump to MDI, and starting a CGM if not previously used This would not include changes to any insulin doses, including basal rates/long acting insulin doses, carbohydrate to insulin ratios and correction factors Current use of non-FDA approved closed-loop or hybrid closed-loop insulin delivery system (e.g. "Loop" or "Open APS") Unwilling to switch to lispro or aspart for the duration of the study's iLet arm (e.g. from Fiasp or Lyumjev) Known hemoglobinopathy (sickle cell trait is not an exclusion) Current participation in another diabetes-related clinical trial, has a medical condition, or use of a medication that, in the judgment of the investigator, could compromise the results of this study or the safety of the participant History of diabetes due to cystic fibrosis, pancreatitis, or other pancreatic disease, including pancreatic tumor or insulinoma, or history of complete pancreatectomy Have a history of intermittently required glucocorticoid treatment (e.g., but not limited to, for the treatment of asthma, inflammatory bowel disease). A1c >11.0% History of diabetic ketoacidosis (DKA) within the past month Electrically powered implants (e.g. cochlear implants, neurostimulators) that might be susceptible to RF interference Established history of allergy or severe reaction to adhesive or tape that must be used in the study  Currently treated with GLP-1 analogue, thiazolidinedione (TZD), sulfonylurea, pramlintide, or SGLT-2 inhibitor medication (use more than 3 months prior to enrollment is acceptable)  a. If using metformin, participants: (i) Must be on a stable dose for 3 months prior to enrollment (ii) Metformin can be continued while the iLet is used  Pregnant (positive urine HCG), breast feeding, plan to become pregnant in the next 2 months, or premenopausal participants who are sexually active without use of contraception Renal failure on dialysis or chronic renal disease with a GFR or eGFR <30mL/min (values within the last two years will be accepted)  Any condition that, in the opinion of the site principal investigator, could interfere with the safe or effective completion of the study.  a. Conditions to be considered by the investigator may include, but are not limited to, the following: (i) Alcohol or drug abuse (ii) Use of prescription drugs that may dull the sensorium, reduce sensitivity to symptoms of hypoglycemia, or hinder decision making during the period of participation in the study (iii)Coronary artery disease that is not stable with medical management, including unstable angina, angina that prevents moderate exercise (e.g. exercise of intensity up to 6 METS) despite medical management, or within the last 12 months before screening, a history of myocardial infarction, percutaneous coronary intervention, enzymatic lysis of a presumed coronary occlusion, or coronary artery bypass grafting (iv) Known history of prolonged QTc interval, malignant arrhythmia, or congenital heart disease (v) Congestive heart failure with New York Heart Association (NYHA) Functional Classification III or IV (vi) History of TIA or stroke in the last 12 months (vii) Untreated or inadequately treated mental illness (viii) History of eating disorder within the last 2 years, such as anorexia, bulimia, or diabulimia or omission of insulin to manipulate weight (ix) History of intentional, inappropriate administration of insulin leading to severe hypoglycemia requiring treatment  Employed by, or having immediate family members employed by Beta Bionics, or being directly involved in conducting the clinical trial, or having a direct supervisor at place of employment who is also directly involved in conducting the clinical trial (as a study investigator, coordinator, etc.); or having a first-degree relative who is directly involved in conducting the clinical trial