To determine the 40 places where young people are moving, 24/7 Wall St. ranked all U.S. counties, county equivalents, and independent cities based on the number of 18 to 34 year-olds who moved to the area from a different county or country in 2017 as a share of the total county population using data from the U.S. Census Bureau’s American Community Survey. Only counties with populations of at least 20,000 were considered. To create a more diverse list of counties, we also excluded areas where 25% or more of the population is enrolled in college or graduate school. Data on median age and home value also came from the ACS. All ACS data are five-year estimates. June 2019 unemployment rates are from the Bureau of Labor Statistics and are not seasonally adjusted. For reference, we also listed a city, town, or borough for each county or county equivalent on this list.