Undercount of Undocumented Residents in the 2020 American Community Survey and Estimates and Trends in the Undocumented Population from 2010 to 2020, by US State and Country of Origin
Robert Warren
December 21, 2022

Abstract
This report shows estimates of the undocumented population residing in the United States from 2010 to 2020, by US state of residence and country of origin. The estimates are based primarily on data from the American Community Survey (ACS) collected annually by the US Census Bureau. As it does each year, the Center for Migration Studies of New York (CMS) assessed the accuracy of the ACS data for 2020 for the noncitizen population from more than 150 countries or areas of origin. The CMS analysis determined that almost one million undocumented residents were omitted from the 2020 ACS. The paper then segues into an extensive discussion of trends in the undocumented population for US state and country of origin over the 2010 to 2020 period.