Despite the tremendous potential of health information technology (HIT) not only to improve the health and well-being of people but also to solve current problems within the health care system, prior research on HIT has provided only limited insights into the behavioral mechanisms behind why people embrace or reject HIT. Given that the benefits of HITs can only be realized when people use them, the examinations of these mechanisms are critical to promote healthy behaviors and improve health outcomes. Therefore, given the importance of understanding these mechanisms as well as the scarcity of research in this area, this dissertation intends to advance IS knowledge by empirically investigating behavioral mechanisms of how individuals’ motivational characteristics influence HIT related behaviors. Specifically, as an overarching behavioral mechanism, this dissertation theorizes that the fit between individuals’ motivations and the technological properties of IS that are designed to fulfill these motivations (i.e., motivational affordances) encourages individuals to use HIT.