Because emotion regulation (ER) is fundamentally a process that unfolds over time, it should be theoretically and empirically modeled as a dynamic temporal process. In this chapter, we argue that an emotion system framework—the self-organizing process of positive and negative feedback among physiological, behavioral, and cognitive components of emotion—provides a parsimonious model of ER as a process, as well as deeper understanding of the emotion-related transformations of adolescence. In Part 1, we explicate the emotion systems framework in which emotion and ER are inseparable at the real-time scale. Therefore real-time ER is best captured as moment-to-moment dynamics of moving in and out of emotional states. Specifically, we focus on ER dynamics in adolescence and contrast the utility of this approach to traditional two-factor models of emotion as distinct from emotion regulation. Ultimately, Part 2 discusses implications of this framework for understanding adolescent development of ER at multiple time scales with challenging proscriptions for research designs. By delineating these dynamic qualities and possibilities for design and analysis, we hope to move the field forward, away from static, trait-like views of ER and toward greater ontological validity.