Inclusion Criteria:

   1. Clinical diagnosis of type 1 diabetes for at least one year and using insulin for at
   least 1 year

   2. Diabetes managed using an insulin pump for ≥ 3 months or with multiple daily
   injections (approximately 1/2 of participants should use a pump and approximately 1/2
   should use MDI)

   3. Age ≥18 years;

   • There is no upper age limit in the Adult RCT Period (instead the exclusion criteria
   are used to restrict the participants to those healthy enough to participate in the
   trial)

   4. HbA1c level <11.0%

   • A point of care or local lab measurement is used to assess eligibility for
   screening.

   5. At least 3 SMBG meter tests daily on average or use of a CGM and 2 or more SMBG meter
   tests daily on average by history

   6. For females, not currently known to be pregnant

   • If female, sexually active, and at risk for pregnancy, must agree to use a highly
   effective form of contraception to prevent pregnancy while a participant in the study.
   A negative urine pregnancy test will be required for all women who are post-menarche
   and pre-menopause who are not surgically sterile. Participants who become pregnant
   will be discontinued from the study.

   7. An understanding of and willingness to follow the protocol and sign the informed
   consent and assent where applicable

Exclusion Criteria:

-The presence of any of the following is an exclusion for the study:

   1. Unable to provide informed consent (e.g. impaired cognition or judgment)

   2. Unable to safely comply with study procedures and reporting requirements (e.g.
   impairment of vision or dexterity that prevents safe operation of the BP, impaired
   memory)

   3. Unable to speak and read English

   4. Currently using for the first time a real-time CGM for < 1 month (Individuals who have
   been using CGM for 1 or more months are eligible)

   5. Current use of non-FDA approved closed-loop or hybrid closed-loop insulin delivery
   system

   6. Current use of insulin glulisine (Apidra) as part of usual diabetes home regimen

   7. Current off-label use of faster-acting insulin aspart (Fiasp) in CSII therapy as part
   of usual diabetes home regimen

   8. Current participation in another diabetes-related clinical trial that, in the judgment
   of the principal investigator, will compromise the results of this study or the safety
   of the participant

   9. Pregnant (positive urine HCG), breast feeding, plan to become pregnant in the next 12
   months, or sexually active and at risk for pregnancy without use of contraception

10. Current alcohol abuse (intake averaging >4 drinks daily in last 30 days) or other
   substance abuse (use within the last 3 months of controlled substances other than
   marijuana without a prescription)

11. Unwilling or unable or to avoid use of drugs that may dull the sensorium, reduce
   sensitivity to symptoms of hypoglycemia, or hinder decision making during the period
   of participation in the study (use of benzodiazepines or narcotics, even if by
   prescription, may be excluded according to the judgment of the principal investigator)

12. Stage 4 renal failure (eGFR <30) or Stage 5 renal failure on dialysis (hemodialysis or
   peritoneal dialysis)

13. History of cystic fibrosis, pancreatitis, or other pancreatic disease, including
   pancreatic tumor or insulinoma, or history of complete pancreatectomy

14. 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

15. Abnormal EKG consistent with increased risk of malignant arrhythmia including, but not
   limited to, evidence of active ischemia, proximal LAD critical stenosis (Wellen's
   sign), or prolonged QT interval (> 440 ms). Other EKG findings, including stable Q
   waves, are not grounds for exclusion as long as the participant is not excluded
   according to other criteria. A reassuring evaluation by a cardiologist after an
   abnormal EKG finding may allow participation.

   • EKG is only required for participants ≥50 years old or with diabetes duration ≥20
   years

16. For participants < 50 years of age and < 20 years since diagnosis: History of
   prolonged QT interval, malignant arrhythmia, or congenital heart disease

17. Congestive heart failure with New York Heart Association (NYHA) Functional
   Classification III or IV

18. History of TIA or stroke in the last 12 months

19. Recent history of diabetic ketoacidosis (DKA) or severe hypoglycemia in the last 6
   months. Severe hypoglycemia is defined as an event that required assistance of another
   person due to altered consciousness, and required another person to actively
   administer carbohydrate, glucagon, or other resuscitative actions. This means that the
   participant was impaired cognitively to the point that he/she was unable to treat
   himself/herself, was unable to verbalize his/ her needs, was incoherent, disoriented,
   and/or combative, or experienced seizure or coma.

20. History of more than 1 episode of DKA requiring hospitalization in the last 2 years

21. History of more than 1 episode of severe hypoglycemia in the last year.

22. Untreated or inadequately treated mental illness (indicators would include symptoms
   such as psychosis, hallucinations, mania, and any psychiatric hospitalization in the
   last year), or treatment with anti-psychotic medications that are known to affect
   glucose regulation.

23. Electrically powered implants (e.g. cochlear implants, neurostimulators) that might be
   susceptible to RF interference

24. Unable or unwilling to completely avoid acetaminophen for duration of study

25. Established history of allergy or severe reaction to adhesive or tape that must be
   used in the study

26. History of eating disorder within the last 2 years, such as anorexia, bulimia, or
   diabulemia or omission of insulin to manipulate weight

27. Current or planned use of SGLT2 inhibitors (prior use more than 3 months prior to
   enrollment is acceptable; SGLT2 inhibitors should not be initiated during the trial)

28. If using GLP1, pramlintide, or metformin must be on a stable dose for 3 months prior
   to enrollment (these agents should not be initiated during the trial)

29. Required use of 2 or more steroid bursts in the 6 months prior to the trial

30. History of intentional, inappropriate administration of insulin leading to severe
   hypoglycemia requiring treatment

31. Any factors that, in the opinion of the site principal investigator or clinical
   protocol chair, would interfere with the safe completion of the study, including
   medical conditions that may require hospitalization during the trial