The COVID-19 pandemic has pushed virtual schooling to the forefront of the national educational landscape. Long-time proponents of this technology quickly positioned digital programs and platforms as the obvious solution for schools that had to close buildings to avoid transmitting the virus. The pandemic exacerbated a trend that NEPC virtual schools' reports have documented since 2013. While it is clear that virtual schools--particularly for-profit virtual schools--are expanding rapidly, there remains little research evidence to support or justify the expansion. Moreover, there is little policymaking at the state level adequate to the task of ensuring the quality of education that virtual school students receive. "Virtual Schools in the U.S. 2021" provides scholarly analyses of the characteristics and performance of full-time, publicly funded K-12 virtual schools; reviews the relevant available research related to virtual school practices; provides an overview of recent state legislative efforts to craft virtual school policy; and offers policy recommendations based on the available evidence. [Contributors to the research brief include Gary Miron, Michael K. Barbour, Luis Huerta, Sheryl Rankin Shafer, Jennifer King Rice, Amanda Glover, Nathan Browning, Shelby Hagle, and Faith Boninger. For "Virtual Schools in the U.S. 2019," see ED595244.]