Although mask wearing has been demonstrated to be an effective strategy to combat the COVID-19 pandemic, it has become a contentious issue. This is evident in the policy shift regarding mask wearing during the pandemic and the varying mask mandates across different states in the United States. This study investigates the relationship between mask wearing and COVID-19-associated discrimination (CAD) over the course of the pandemic (March 2020 through May 2021), and differences between states with and without mask mandates. This study utilized three-level longitudinal analyses to analyze a longitudinal panel data from a nationally representative sample of U.S. adults enrolled in the Understanding America Study (UAS). The experiences of CAD were much higher for those wearing a mask than those not wearing a mask before August 2020, but this pattern was reversed afterward. Another notable finding was that mask wearers reported greater CAD in states with no mask-wearing mandate than the ones in states with mask mandates. In contrast, the pattern was reversed for nonmask wearers. The findings highlight the importance of inclusiveness and openness when relatively new health practice is introduced during a public health crisis.