A brief review of biological and psychological classification systems reveals that existing taxonomies have focused on discrete, static classifications of panic. Our paper introduces a dynamic, idiographic phenomenological system to characterize panic as it occurs across the anxiety disorders. The model consists of four grids, each with four quadrants, that focus on the degree and specificity of physiological change, catastrophic cognitions, and somatic sensations, as well as the extent and type of affect experienced. Preliminary data from an ambulatory home monitoring study are presented to demonstrate the utility of the model. A primary contribution of the model is that it increases precision and emphasizes assessment across measurement domains. The proposed system may provide the basis for future research in a number of areas, which are delineated.