We introduce a theoretical framework for conceptualizing psychological well-being as a process that unfolds over short and longer time-scales. We argue that this framework can be especially useful for studying the change mechanisms in psychological well-being within the context of mobile Health (mHealth) interventions. Four lines of process-oriented research are considered within this framework to inform the scientific exploration of psychological well-being in the context of mHealth interventions. First, we explore psychological well-being functioning via person-specific characteristics. Second, we discuss key characteristics of change as a result of mHealth interventions. Third, we review evidence that interventions conduce towards psychological well-being through an underlying process of skill development through practice. Fourth, we discuss intervention response heterogeneity within this framework. The approach we outline is intended to articulate currently unanswered, process-oriented research questions about psychological well-being interventions, how they work, and a methodological path forward for exploring them.