|Employees constantly transition from work to home roles, crossing boundaries between these roles. Drawing on boundary and border theory, work-life boundary management (WLBM) consists of behaviors that help create and maintain boundaries towards effective work-life balance (McDowall & Lindsay, 2014). WLBM was first examined and validity evidence provided, then it was tested in a longitudinal mediation model. In Study 1, WLBM was found to consist of 27 behaviors representing six competencies: boundary awareness, clarifying boundaries, organizing, framing, scheduling, and partnering. A follow-up study confirmed these results. Study 3 provided validity evidence of WLBM by uncovering the positive relationships between work and family segmentation/integration preference and enactment, work satisfaction, as well as the negative relationship with role conflict. Then, Study 4 attempted to explain the complex relationship between segmentation/integration and satisfaction through WLBM. A three-wave survey spanning 6 months was administered to a large online sample. The relationship between segmentation/integration and work and family satisfaction was analyzed in four longitudinal mediation models with WLBM as the mediator. Results were not significant. Discussion and recommendations for future research on segmentation/integration and WLBM is included.