Before the 2020-2021 school year, policymakers and parents confronted the uncertain trade-offs implied by the health, educational, and economic consequences of offering instruction remotely, in person, or through a hybrid of the two. Most public schools in the United States chose remote-only instruction, and enrollment fell dramatically (i.e., a loss 1.1 million K-12 students). We examine the impact of these choices on public-school enrollment using panel data that combine district-level information on enrollment and instructional mode. We find offering remote-only instead of in-person instruction reduced enrollment by 1.1 percentage points (i.e., 42% greater disenrollment). The disenrollment effects of remote instruction are concentrated in kindergarten and, more modestly, elementary schools. We do not find evidence that hybrid instruction had an impact.