“Most people without health insurance coverage had a high school education or less. People who did not complete high school made up a much larger part of the uninsured population (26.9 percent) than the overall population (11.8 percent).

The uninsured population was also disproportionately more likely to live in poverty. About 1 in 3 uninsured workers were in service occupations, compared with about 1 in 5 workers in the U.S. overall.”

https://www.census.gov/library/stories/2018/09/who-are-the-u...