The average cost of a college education in the United States is $35,720 a year — three times higher than it was two decades ago. While rising tuition costs are discouraging many Americans from enrolling, a college education is an investment that can increase access to career opportunities, improve job security, and increase earning potential. 

Nationwide, an estimated 32.1% of American adults 25 and older have a bachelor’s degree or higher. Educational attainment rates vary considerably across the country, however, and in every state, there is at least one ZIP code where the share of adults with a bachelor’s degree is well below the national average. 

Using education data from the U.S. Census Bureau, 24/7 Wall St. identified the least educated ZIP code in every state. 

According to the Bureau of Labor Statistics, the unemployment rate among adults with a four-year college education was 5.5% 2020. Meanwhile, the jobless rate among those with no more than a high school diploma was 9.0%. In all but eight ZIP codes on this list, the five-year average unemployment rate among the 25 to 64 year population is higher than the comparable jobless rate across the state as a whole. 

In addition to being better protected from unemployment, Americans with a bachelor’s degree also tend to have higher salaries. The average weekly wage for a college-educated worker in the United States is about 67% higher than it is for those with no more than a high school diploma — and in places with lower educational attainment, incomes also tend to be lower than average. In nearly every ZIP code on this list, the typical household earns less in a year than the statewide median household income.

Click here to see every state’s least educated ZIP code
Click here to see our detailed methodology