1. After initial eligibility is determined, informed consent and assent are obtained from the parent/guardian and subject.
2. Subjects will have the following tests performed:
* Hemoglobin A1c (using the DCA2000 or equivalent device)
* Oral glucose tolerance test to obtain fasting and 2 hour plasma glucose levels
* Anti-GAD, anti-IA2 and anti-insulin antibodies
* Subjects with an HbA1c \>6.0% and/or fasting glucose levels \>100 and/or 2 hour glucose levels \>140 will be discontinued from the study.
3. Subjects with normal A1c and glucose levels will be provided with an RT-CGM and home glucose meter (HGM)
4. An RT-CGM sensor will be inserted and initiated by study personnel.
5. Subjects who would like to wear 2 sensors will be given 2 of the same type of RT-CGM.
6. Subjects will be instructed to wear the sensor for 3-7 days (depending on the type of device) and measure the blood glucose on the HGM as needed to calibrate the sensor.
7. Subjects will return to the clinical center after the 3-7 days of sensor wear to return the RT-CGM and HGM.
* If the subject has less than 48 hours of sensor data he or she will be asked to wear another sensor and return 3-7 days later.
