The goal of the decennial census is to count everyone once, only once, and in the right place. However, the Census Bureau has historically overcounted certain groups—including white people—while undercounting others—including people of color, young children, and people experiencing homelessness. These gaps undermine the fairness of the census and contribute to an inequitable distribution of political power and federal resources for programs that support economic security, health, and education. This working paper examines the self-response rates to the 2020 Census by various socio-economic, demographic, and housing characteristics in order to gain timely insights into the potential accuracy of the 2020 Census.