California’s population is among the most difficult to count. California has 10 out of 50 counties nationwide with the largest hard to count populations, 12% of the total U.S. population and 25% of the nation’s undocumented population.

Hard to Count populations in California include: people of color, young children, immigrants, and people with limited English proficiency, renters, highly mobile people, people who are unemployed and people who are homeless.