In six states, at least one in five working adults is uninsured, according to the report, which looked at government data. In 38 other states, at least one working adult in every 10 does not have health insurance.

The report also found that adults who do not have health insurance experience significant gaps in medical care compared to those who do.

The organization released the report to coincide with a campaign to raise awareness, Cover the Uninsured Week. Nearly 1,500 public events will take place around the country during the week. Specific events are designed to help uninsured individuals get services and provide information to small business owners struggling to provide health insurance for their employees.

The effort is co-chaired by Presidents Gerald Ford and Jimmy Carter.

"For far too many years, our nation has not lived up to its full potential by delaying the day when all Americans will have health care coverage," says Carter. "Leaders of every one of our communities need to commit themselves to fulfilling this basic human right."

The study found that states with the highest rates of uninsured residents among all employed or self-employed adults include Texas (27 percent), Louisiana (23 percent), Mississippi (22 percent), and New Mexico (22 percent). States with the lowest uninsured rates among all employed or self-employed adults include Minnesota (7 percent), Hawaii (7 percent), Maryland (8 percent), and Iowa (9 percent).