A prospective, multicenter evaluation of performance and safety of the Eversense Gemini System with flash glucose measurement feature. The purpose of this clinical investigation is to evaluate the accuracy of the Gemini System with new technological flash glucose monitoring (FGM) feature enhancements compared to reference glucose measurements and the Eversense 365 CGM System. The investigation will also evaluate safety of the Gemini System usage.

Inclusion Criteria:

Subjects meeting all of the following inclusion criteria will be included in this study:

1. Subjects ≥18 years of age
2. Clinically confirmed diagnosis of diabetes mellitus for ≥1 year
3. Subject has signed an informed consent form (ICF) and is willing to comply with protocol requirements

Exclusion Criteria:

Subjects meeting any of the following exclusion criteria at the time of screening will be excluded from this study:

1. History of severe hypoglycemia in the previous 6 months. Severe hypoglycemia is defined as hypoglycemia resulting in loss of consciousness or seizure.
2. History of diabetic ketoacidosis requiring emergency room visit or hospitalization in the previous 6 months.
3. Subjects with gastroparesis.
4. Female subjects of childbearing capacity (defined as of childbearing age and as not surgically sterile or not menopausal for ≥ 1 year) who are lactating or pregnant, intending to become pregnant, or not practicing birth control during the course of the study.
5. A condition preventing or complicating the placement, operation, or removal of the sensor or wearing of transmitter, including upper extremity deformities or skin condition.
6. Symptomatic coronary artery disease; unstable angina; myocardial infarction, transient ischemic attack or stroke in the past 6 months; uncontrolled hypertension (systolic>160 mm Hg or diastolic >100 mm Hg at time of screening); current congestive heart failure; history of cardiac arrhythmia (benign PACs and PVCs allowed). Subjects with asymptomatic coronary artery disease (e.g., CABG, stent placement or angioplasty) may participate if negative stress test within 1 year prior to screening and written clearance from Cardiologist documented.
7. Hematocrit <38% or >60% at screening
8. History of hepatitis B, hepatitis C, or HIV
9. Current treatment for a seizure disorder unless written clearance by neurologist to participate in study.
10. History of adrenal insufficiency
11. Currently receiving (or likely to need during the study period): immunosuppressant therapy; chemotherapy; anticoagulant/antithrombotic therapy (excluding aspirin); topical glucocorticoids over sensor site only; antibiotic for chronic infection (e.g., osteomyelitis, endocarditis)
12. A condition requiring or likely to require magnetic resonance imaging (MRI)
13. Known topical or local anesthetic allergy
14. Known allergy to glucocorticoids
15. Any condition that in the investigator's opinion would make the subject unable to complete the study or would make it not in the subject's best interest to participate in the study. Conditions include but are not limited to psychiatric conditions, known current or recent alcohol abuse or drug abuse by subject history, a condition that may increase the risk of induced hypoglycemia or risk related to repeated blood testing. Investigator will supply rationale for exclusion
16. Participation in another clinical investigation (drug or device) within 2 weeks prior to screening or intent to participate during the study period
17. The presence of any other active implanted device (as defined further in the protocol)