In the aftermath of discrete disasters, how families discuss the event has been linked with child well-being. There is less understanding, however, of how family communication affects adjustment to a protracted and ongoing public health crisis such as the COVID-19 pandemic. The present research leveraged a large longitudinal sample of families (N = 1884) across the United States and Canada to investigate factors that predicted family communication styles (active versus avoidant communication) about the COVID-19 pandemic and examined the longitudinal sequelae of mental health outcomes for youth associated with different family communication styles. Parents of youth between 5 to 17 years old completed surveys about their own mental health, their child’s mental health, and family communication about the COVID-19 pandemic at two time points 6 months apart. Overall, findings indicated that poorer parental mental health was related to greater use of avoidant communication, and avoidant communication styles were associated with poorer youth mental health over time. Findings suggest potential perils of avoidant family communication about ongoing threats and can help identify families at risk of negative mental health outcomes.