The purpose of this paper is to examine gaps in our understanding of the heart failure experience and describe the use of Trajectory of Chronic Illness Theory to bridge these gaps. New pharmacotherapeutic strategies have improved survival in heart failure, but research has consistently shown that clinical outcomes in these patients do not depend on physiologic variables alone. Psychological, behavioral, environmental, social and socioeconomic variables also contribute to a patient's ability to manage chronic illness. However, we have not yet identified the essential elements in helping patients engage in self-management and adhere to increasingly complex medical regimens. Theoretical models facilitate disciplinary integration, providing a comprehensive and cohesive foundation for building better science. The Trajectory of Chronic Illness Theory is particularly salient for heart failure because of its emphasis on patients' ability to manage a chronic illness. By using theory to explore gaps in our understanding of the heart failure experience, investigators may be able to develop more targeted interventions to help patients manage heart failure.