Using a sample of octogenarians from the Swiss Interdisciplinary Longitudinal Study on the Oldest Old, the authors investigated the predictive validity of an expanded working definition of frailty based on deficiencies in mobility, memory, energy, and physical or sensory capacities and analyzed the resulting health transitions. The five domains were considered as predictors of the onset of dependence in activities of daily living (ADLs) and death using logistic multilevel and Cox survival regression models. Health transitions were studied with Markov chains. Deficiencies in memory, energy, and sensory capacities contributed to the prediction of the onset of ADL dependence and death in participants free of physical pains and mobility impairments. With two domains affected, frailty in very old persons indicated an increased risk of adverse outcomes. The study of transitions showed that ADL-independent frailty was a highly probable and relatively long transitional stage between robustness and ADL dependence.