The COVID-19 pandemic has spurred global change from traditional office-based work to remote work, driven by policy interventions, and resulting in a significant number of employees worldwide transitioning to working from home. Existing research presents conflicting evidence regarding the relationship between remote work and productivity. However, few have examined the specific mechanisms through which remote work affects productivity. Given this, the present study bridges this gap by examining changes in job assignment as one mechanism in which working from home affects labor productivity. We empirically examine the impact of work-from-home (WFH) on job tasks using original data collected before and during the pandemic. Our results demonstrate that WFH increases non-routine analytic tasks and decreases routine manual tasks, while non-routine interactive, routine cognitive, and non-routine manual tasks remain unchanged. Furthermore, the negative impact of WFH on routine manual tasks is more significant for the groups that had more routine manual tasks before the pandemic. Meanwhile, the positive impact on non-routine analytic tasks is more pronounced for employees with fewer non-routine analytic tasks before the pandemic. Finally, through such task changes, WFH leads to higher wage rates. Our findings suggest that the switch to WFH and increased use of information and communication technology capital increases the input for non-routine tasks performed by labor, and, in turn, increases labor productivity.