An examination of clinical and empirical evidence raises questions about how best to teach youngsters with insulin-dependent diabetes mellitus (IDDM) to assume responsibility for self-care. The thesis of this paper is that age alone gives insufficient information. Evidence is reviewed suggesting that caretakers consider a child's fund of diabetes knowledge, degree of cognitive development, actual performance of diabetes-related tasks, locus of control, and family environment to determine how and when to transfer responsibility for self-care to a young person. In addition, evidence is presented that suggests that shared responsibility between parent and child is most highly correlated with better metabolic control. It is concluded that informed decisions about self-care are best made by considering a variety of factors, with age being merely a guidepost.