Background: As the COVID-19 pandemic spread across the US and protective measures to mitigate its impact were enacted, parents and children experienced widespread disruptions in daily life. The objective of this national survey was to determine how the pandemic and mitigation efforts affected the physical and emotional wellbeing of parents and children in the US through early June 2020. Methods: In June 2020, we conducted a national survey of parents with children under age 18 to measure changes in health status, insurance status, food security, utilization of public food assistance resources, childcare and use of health care services since the pandemic began. Results: Since March 2020, 27% of parents reported worsening mental health for themselves, and 14% reported worsening behavioral health for their children. The proportion of families with moderate or severe food insecurity increased from 6% before March 2020 to 8% after, employer-sponsored insurance coverage of children decreased from 63% to 60%, and 24% of parents reported a loss of regular childcare. Worsening mental health for parents occurred alongside worsening behavioral health for children in nearly 1 in 10 families, among whom 48% reported loss of regular childcare, 16% reported change in insurance status, and 11% reported worsening food security. Conclusions: The COVID-19 pandemic has had a substantial tandem impact on parents and children in the US. As policymakers consider additional measures to mitigate the health and economic effects of the pandemic, they should consider the unique needs of families with children. (author abstract)