This article reviews the presence of family theory in health-care research. First, we demonstrate some disconnect between models of the patient, which tend to focus on the individual, and a large body of research that finds that relationships influence health. We summarize the contributions of family science and medical family therapy and conclude that family science models and measures are generally underutilized. As a result, practitioners do not have access to the rich tool kit of lenses and interventions offered by systems thinking. We propose several possible ways that family scientists can contribute to health-care research, such as using the family as the unit of analysis, exploring theories of the family as they relate to health, and suggesting greater involvement of family scientists in health research.