Nationwide, the median annual household income is $57,652. It varies widely by state, from $42,000 in Mississippi to nearly $79,000 in Maryland. Despite these differences, each U.S. state — even the poorest — is home to at least one county in which the median annual household income exceeds the national median. In some states, the wealthiest county’s median income is more than double the nation’s median.
Many of the wealthiest counties are within commuting distance of major cities. In all but seven states, the wealthiest county is located in a major metropolitan area. These major population centers are home to a greater concentration of high-paying jobs, which can help keep unemployment low and incomes high.
24/7 Wall St. reviewed the median household income in all U.S. counties and county equivalents to identify the wealthiest county in each state.
Nearly every state’s wealthiest county has a relatively well-educated population. In 46 states, the bachelor’s degree attainment rate in the wealthiest county is higher than the statewide rate.
The four exceptions — counties in North Dakota, Wyoming, Nevada, and Montana — are located in resource-rich areas. In these states, the richest county’s economy is dependent on oil or mineral extraction. These industries are often the source of high-paying jobs that do not require a college degree.
To identify the richest county in each state, 24/7 Wall St. reviewed median annual household incomes for each U.S. county using 5-year estimates from the U.S. Census Bureau’s 2017 American Community Survey. We only considered counties with income estimates with a maximum 10% margin of error. We also reviewed in each county the percentage of adults who have earned a bachelor’s degree or higher, poverty rates, and median home values from the ACS. The major metro area noted is the metropolitan statistical area the county lies within. Unemployment rates from the Bureau of Labor Statistics are not seasonally adjusted and are for October 2018.