Education levels are on the rise in the United States. According to newly released estimates from the U.S. Census Bureau’s American Community Survey, 79.9 million American adults – 35% of the nation’s 25 and older population – have a bachelor’s degree or higher. As recently as five years ago, fewer than 33% of American adults had a bachelor’s degree.

A college education has long been a key driver of upward mobility in the United States. However, enrollment costs at colleges and universities have soared in recent years, making a four-year postsecondary education prohibitively expensive for many working- and middle-class families. 

Costs are not the only consideration to weigh before attending college. For some small business owners and those pursuing a career in the trades, the military, law enforcement, or public safety, a bachelor’s degree may not be necessary. (Here is a look at the highest paying jobs you can get without a college degree.)

In some parts of the country, Americans are far less likely to have a four-year college degree than in others. Using 2021 ACS data, 24/7 Wall St. identified the least educated states in the country. In each of the 30 states on this list, the share of adults with at least a bachelor’s degree is below the 35% national average. 

While the decision to attend college is a personal one, bachelor’s degree holders have some clear advantages in the workforce, including higher earning potential. Median earnings in 2021 among workers with a bachelor’s degree stood at $61,073, compared to $35,019 among working adults with no more than a high school diploma. Due in part to lower than average bachelor’s degree attainment rates, in nearly every state on this list, median earnings across all working adults are below the $45,943 national median. (Here is a look at the states where a college education pays off the most.)

Not only does a college degree open up higher-paying job opportunities, but it also provides greater job security. According to the Bureau of Labor Statistics, the unemployment rate among bachelor’s degree holders stood at 3.5% in 2021, well below the 6.2% jobless rate among those with only a high school diploma. Despite this broader trend, many states on this list had a better than average unemployment rate last year.

Click here to see America’s least college-educated states.

Click here to see our detailed methodology.