AbstractBoth in the research literature as well as in popular media, the topic of “work-life” balance receives much attention, particularly for the age group of middle-aged adults. There is evidence for both, positive and negative spillover effects across life domains. This chapter provides a theoretical and empirical overview of the different types of inter-domain relationships, concepts of boundary management, and models of spillover effects on health and well-being. Adopting a lifespan perspective, we review the literature on spillover effects by focusing on multiple goal pursuit in the life domains of work, family, and leisure in middle adulthood. During this “rush hour” of life, middle-aged adults face the challenge of managing their scarce resources (e.g., time, energy) in order to achieve a successful “work-life balance.” Accordingly, we present empirical studies addressing the interplay between goal pursuit, boundary management, inter-domain conflict and facilitation, as well as spill- and crossover effects at the work-family interface. In addition, this chapter considers both exhaustion and recovery as key outcomes of spillover effects across life domains and highlights recommendations for boundary management in middle adulthood. Finally, this chapter outlines promising routes for future research on spillover effects between work, family, and leisure.