Practice and Policy Oriented Abstract This article views social media for work not only as technologies that enable people to do certain things, but also as contexts with emerging norms and roles in which people participated. As they do so, people are confronted with opportunities and challenges that are inherent to social media polycontextuality, that is, with multiple social media–based contexts of relevance to work. This study offers guidance for people on how their participation in multiple social media contexts affects their work positively and negatively and how they can manage the associated opportunities and challenges. It also reveals how people’s engagement with social media polycontextuality may change as their employment status and work experiences evolve. Moreover, this study holds managerial implications by bringing awareness to how employees’ participation in social media contexts bypasses the organization and, thus, their typical purview but is still associated with work rather than leisure. Managers can understand better their employees’ situations and examine how social media contexts affect them within and beyond organizational boundaries and shape what they can or cannot do in their work. A better understanding of social media polycontextuality also brings managers new insights to communicate with employees.