open access journal The COVID-19 pandemic has posed major challenges, of which food insecurity is one, to countries across the world. A number of policies have been put in place in response to the development of the outbreak. In this paper, I investigate the impacts of one of these policies, the reopening of the economy, on food security. Using a recent large-scale household survey in the United States, I find that food insecurity is a major problem that could adversely affect people's health. Using a report on containment policy across states in the United States to construct the level of this policy, I also find that this policy reduced the likelihood of food insecurity. While the overall impact of this policy is expected, how it influenced the causes of food security is more interesting. In particular, while it helped to increase the availability of food to the people in need, it decreased their ability to buy food. Not only reopening policy increased the expenses on food, which made food less affordable, it also had adverse effect on people's health which prevented them from going out to buy food. I also show how effective the multiple food programs were in the presence of reopening policy. These findings provide valuable evidence to policy makers in mitigating the impacts of the COVID-19 crisis.