This study examines whether transitioning from cellular offices to an activity-based flexible office (A-FO) impacts employee absenteeism over time. Based on privacy theory, we hypothesized that changing from cell offices to an A-FO setting would lead to increased employee absenteeism. We further assumed that longer-tenured and female employees would experience greater difficulty with the transition, leading to more absenteeism among these groups. Using a sample of 2,017 white-collar workers tracked over 8 years, we quasi-experimentally investigated if absenteeism in the group with the office design intervention (1,035 individuals) differed from the control group (982 individuals). In the difference-in-difference (DiD) framework, nested negative binomial regression showed no difference in absenteeism between the intervention and control groups. However, a three-way interaction revealed that long-term employees showed higher absenteeism when switching to an A-FO. We discuss our contributions and the implications for corporate leadership, human resources, and change management.