The purpose of the study is to compare two interventions for preparing diabetic teens and young adults for transition from pediatric to adult diabetes care.

One will represent a short-term intensive social-behavioral intervention supported by peer-to-peer social networking in which subjects receive "usual care" from their current diabetes provider outside the parameters of the study. The second intervention will be a traditional transition clinic model, where subjects will receive the standard of diabetes care from a team of combined pediatric and adult practitioners and educators, with added educational modules and behavioral evaluation and support designed to facilitate the transition to adult care (i.e., that foster "developmentally tailored care"). The first is a much less intensive intervention from the standpoint of the providers and gives special prominence to peer support; the second is provider-intensive. The goal of both interventions is to improve self-efficacy (confidence in taking ownership of and managing one's diabetes); i.e., to prepare the patient to move from primary support by family and providers to a reliance on self-ownership and self-management as a responsible, independent adult.

Optional sub-study available for parents, spouses, and significant others.

Inclusion Criteria:

• Age 16-29
• Diagnosis of type 1 diabetes, or type 2 diabetes managed with insulin, at least one year prior to study initiation
• English-speaking
• Some form of private or public (e.g., Medicaid) health insurance

Exclusion Criteria:

• Cystic fibrosis-related or pancreatitis-related diabetes
• Diabetes related to a known specific genetic defect such as Down's Syndrome, Lipoatrophic Diabetes, Leprechaunism or Rabson-Mendenhall Syndrome, etc.
• Chronic liver disease
• History of chronic renal failure
• Serious psychiatric illness that in the judgment of the investigators would preclude the individual's ability to complete the study
• Pregnant or planning to become pregnant within 6 months