The decennial census (census) is a complete count of everyone residing in the United States. This includes people of all ages, races, ethnic groups, citizens and non-citizens. It is mandated by Article 1, Section 2 of the Constitution and takes place every 10 years.
The next census will take place April 1, 2020. The goal of Census 2020 is to count everyone once, only once, and in the right place.