The past decade has seen great advances in our understanding of the pathogenesis of IDDM. This knowledge has led to investigate use of a battery of immunologic, genetic, and metabolic tests for identifying people with prediabetes. Therapies designed to arrest autoimmunity have been associated with incomplete responses and the complications of immunosuppression. Ultimately, we hope that IDDM can be eradicated by inducing tolerance to the diabetogenic autoantigen(s).