Population-based screening for diabetes mellitus in non-pregnant adults remains controversial. For a screening strategy to be successful, patients identified by surveillance will have to have better outcomes than if they had been diagnosed at a later, more symptomatic phase of disease. However, little is known about the fate of patients diagnosed with diabetes by screening. Additionally, while about half of the cases of diabetes among the general population at any given time are undiagnosed, the prevalence of undiagnosed diabetes among veterans is unknown. The annual incidence of diabetes among veterans is also unknown.