Inclusion Criteria:

• Clinical diagnosis of type 1 diabetes and using daily insulin therapy for at least one year The diagnosis of type 1 diabetes is based on the investigator's judgment; C peptide level and antibody determinations are not needed.
• Age 12.0 years to less than 18.0 years
• HbA1c <8.0%
• Use of basal: bolus insulin therapy with either an insulin pump or glargine with MDI of a short-acting insulin for at least 6 months (approximately 5 pump and 5 MDI users will be enrolled)
• Availability of home computer to download the CGM
• For females: not currently pregnant, negative pregnancy test, and not intending to become pregnant during the next 3 months
• Parent/guardian and subject understand the study protocol and agree to comply with it
• Informed Consent Form signed by the parent/guardian and Child Assent Form signed by the subject if required by IRB

Exclusion Criteria:

• Severe hypoglycemic event (seizure or coma) or diabetic ketoacidosis in the past 6 months
• Cardiac disease, including prolonged QT interval on EKG or pathologic arrhythmia
• An EKG will be done either prior to the CRC admission or during the CRC admission prior to the first dose of terbutaline
• Treatment for hypertension or blood pressure exceeding the 90th percentile for age and height
• Current treatment for a seizure disorder
• Asthma if treated with systemic or inhaled corticosteroids in the last 6 months or with a beta adrenergic agonist more than once a month
• Cystic fibrosis
• Use of MAO inhibitors, tricyclic antidepressants, or beta blockers
• Current use of oral/inhaled glucocorticoids or other medications, which in the judgment of the investigator would be a contraindication to participation in the study.
• Inpatient psychiatric treatment in the past 6 months for either the subject or the subject's primary care giver (i.e., parent or guardian).
• Medical condition that in the judgment of the investigator might interfere with the completion of the protocol