The Affordable Care Act was created to allow all Americans to have health services, reimbursed with little financial burden to the patient or family. The ACA’s requirement for all citizens to have health coverage meant that many people who never realized they were eligible for Medicaid enrolled in the program, the best of the ACA consequences.

The early results, published in a study by researchers at Harvard T.H. Chan School of Public Health, are encouraging. Two years after Medicaid coverage was expanded under the ACA in Kentucky and Arkansas, low-income adults in these states received more primary and preventive care, made fewer emergency department visits, and reported higher quality care and improved health compared with low-income adults in Texas, which did not expand Medicaid. The study’s findings provide new evidence for states still on the fence about whether or how to expand coverage to low-income adults.

The study, published August 8, 2016, in JAMA Internal Medicine, also found that it did not matter how much a state expands its coverage, just that the coverage is expanded. To date, more than 30 states and the District of Columbia have chosen to expand coverage under the ACA. However, there are still many states where the debate on Medicaid expansion continues. In Arkansas and Kentucky, newly elected governors have proposed scaling back or overhauling their state’s expansions.

The study surveyed approximately 9,000 low-income adults in Arkansas, Kentucky and Texas from late 2013 to the end of 2015. The results showed that in that two-year period, the uninsured rate dropped from 42 percent to 14 percent in Arkansas and from 40 percent to 9 percent in Kentucky. These drastic drops were significant when compared with a much smaller change in Texas, which went from 39 percent to 32 percent.

The Medicaid expansion was also associated with significantly increased access to primary care, improved affordability of medications, reduced out-of-pocket spending, reduced likelihood of emergency department visits, and increased outpatient visits. Screening for diabetes, glucose testing among people with diabetes, and regular care for chronic conditions all increased significantly after expansion. Quality of care ratings improved significantly, as did the number of adults reporting excellent health.

Many of these quality changes were more apparent in 2015 than in 2014. Previous studies looking at the early impact of Medicaid expansion had shown increased affordability and access to care, but limited impact on utilization, preventive care and health. Those earlier studies most likely underestimated the ACA’s impact because the researchers were using data from just the first year or 18 months of coverage, and it may be that the benefits of expansion take longer to unfold.