Certain states are also lagging in health care access. Texas, Nevada and Florida top the nation in uninsured with more than 1 in 5 people living without health insurance, according to 2011 data. Nationwide, the average is closer to 1 in 6 people uninsured. 

Massachusetts, which began implementing a statewide health insurance mandate in 2006, has the lowest numbers of uninsured in the nation at 1 in 23 individuals, a scenario that bodes well for the ACA, which was modeled, in part, after the Massachusetts plan. 

Some states, like Minnesota, have been doing relatively well all along, and Blewett attributes its success to the state's sound economy with a set of large employers with a tradition of providing comprehensive health coverage, as well as a public health insurance program that covers broad classes of individuals, including homeless men. 

Texas, on the other hand, has a very different kind of economy, and a weak public safety net. 

“Texas has a lot of small employers, it's a different culture of coverage” said Blewett. “It's very hard for small employers to provide coverage.”

The landscape is about to dramatically change with the implementation of the ACA in 2014. The individual mandate requires every citizen to purchase health insurance through a marketplace of regulated health care plans, known as exchanges, or enroll in a public program. Blewett said the mandate should dramatically lower the number of uninsured across the country.

“People are going to have to have coverage. If you say you can't afford it there are programs for you now,” she said. “We will need a lot of education of the public and targeted toward the low-income population.”

However, there will still remain a checkerboard of health insurance access across the states. The U.S. Supreme Court's 2012 decision on the ACA effectively allowed states to forfeit federal funds and opt-out of the expansion of Medicaid to all individuals in poverty. This means there will still be a gap in coverage for low-income individuals (primarily childless adults, or adults without dependent children) in more than a dozen states that have opted out.

“We will see how far the states go that did opt in, versus those that did not,” said Blewett. “Those states that did expand will see more coverage, I imagine.”

Hispanics may also still lack health insurance because of the larger numbers of undocumented workers, as well as immigrants living under the five-year-ban for public services, Blewett said.

SHADAC will be releasing new data as early as next year on the number of people who sign up for the health insurance exchanges. But a clear picture of how the ACA has impacted the uninsured will take longer.

Sources and Notes:

SHADAC analysis of American Community Survey (ACS) and Medical Expenditure Panel Survey-Insurance Component (MEPS-IC) data.

 Coverage estimates reflect primary source of coverage. If multiple sources of coverage were reported for an observation, primary source of coverage was assigned in the following order:

 1) Medicare (for people age 19 or older)

 2) Employer-sponsored insurance (ESI)

 3) Medicaid/CHIP

 4) Nongroup

 5) Medicare (for people age 18 or under).