According to the American Community Survey (ACS), about one-quarter (24.8 percent) of the U.S. population over the age of 3 was enrolled in school in 2021. This report provides a comprehensive picture of the state of school enrollment using recently published data from the ACS. It outlines modern enrollment trends while also offering comparisons to past levels of enrollment. More specifically, this report covers the time of the COVID-19 pandemic that was characterized by school closures, expanded remote learning, and decisions to delay school enrollment from both schools and families. We pay specific attention to two levels of schooling that saw notable shifts from 2019 to 2021 -  preschool enrollment and college enrollment - and we examine whether certain demographic groups or geographic areas were more impacted than others. (author abstract)