A report from researchers at the Urban Institute, with funding from the Robert Wood Johnson Foundation, finds the rate of people without health insurance in Delaware fell by 5.4% between 2013 and 2017.

Researchers say Delaware had a modest reduction in its uninsured rate compared to other states between 2013 and 2017 because the state already had low uninsurance rates to begin with.

On average, states like Delaware, which had the lowest uninsured rates prior to the Affordable Care Act and expanded Medicaid, saw significantly smaller gains compared to similar states that had high uninsurance rates pre-ACA. While the state already had high coverage rates, Delaware’s decision to expand Medicaid fueled progress.

“The percentage of people who remain uninsured differs widely across states largely because of choices state lawmakers have made,” said Mona Shah, of the Robert Wood Johnson Foundation. “States that took full advantage of the Affordable Care Act quickly saw expanded access to affordable coverage for their uninsured residents.”

The report is available at rwjf.ws/31u4PWW.

Researchers examined the insurance landscape before and after implementation of the ACA and created a framework that grouped states into five categories, based on similar attributes: high or low uninsured rate prior to the ACA, whether the state expanded Medicaid or not, and marketplace enrollment by subsidy-eligible individuals. Changes in the employer-sponsored insurance market, average incomes and other factors were also considered.