Population health management (PHM) has increasingly been mentioned as a concept to realize improvements in population health and quality of care while reducing cost growth (the so-called Triple Aim). The concept of PHM has been used in various settings and has been defined in different ways. This study compared the definitions of PHM used in the literature in order to improve the understanding and interpretation of the concept of PHM. A scoping literature search was performed for papers published between January 2000 and January 2015 that defined PHM. PHM definitions were summarized, focusing on: (1) overall aim, (2) PHM activities, and (3) contextual factors. Eighteen articles were retrieved. The overall aim was defined in terms of health (N = 14), costs (N = 8), and/or quality of care (N = 10). Definitions varied regarding the description of PHM activities, though all definitions contained elements in common with disease management and health promotion. Data management, Triple Aim assessment, risk stratification, evaluation, and feedback cycles were less likely to be mentioned. Contextual factors were scarcely brought forward in the definitions. Moderate variations were found across definitions in the way PHM was conceptualized. Frequently, essential elements of PHM were not specified. Differences in conceptualizations of PHM should be taken into account when comparing PHM initiatives that are working toward improvements in population health, (experienced) quality of care, and reduction of costs.