Work-family life is becoming increasingly complex for the modern working parent, making boundaries that define aspects of the interface evermore important yet presenting their own challenges in ongoing work-family management. However, the boundary management literature has emphasized general preferences or tendencies that behaviorally integrate or segment work and family, and predominantly treated these boundary constructs as stable. Consequently, little is known about the essence of doing boundary work as a practice in and of itself. We therefore sought to understand how people construct, control, and change their boundaries by taking an inductive approach to explore the experiences of remote working parents who had to undertake the full-time care of their children during the pandemic. Taking a grounded theory approach to analyze two distinct sources of qualitative data, we uncover the cognitive nature of boundary work that encompasses multiple stages: anticipating boundary needs, boundary planning, regulating boundary implementation, and adaption of boundaries. Altogether, we incorporate existing research with these findings to build new theory of boundary work as a thoughtful and effortful process that unfolds through pre- to post-enactment phases—with these direct and novel explanations for how and why people manage their boundaries having salient theoretical and practical implications.