survey released on June 19 by the nonpartisan Kaiser Family Foundation found that 57% of individuals who purchased health insurance through the exchanges, or “marketplaces,” established under the Affordable Care Act (ACA) were previously uninsured. Previous studies by McKinsey & Co. and RAND Corp. had estimated that only one-third or less of exchange enrollees were previously uninsured.

Many critics of the ACA had claimed that most exchange customers would already have had other insurance coverage, and predicted that the ACA would not succeed in significantly reducing the number of uninsured. However, Kaiser’s study reported that most new enrollees had been uninsured for two years or more, and a significant percentage had been without coverage for more than five years. 

The qualified success of the exchanges is undoubtedly due, in part, to the availability of income-based premium subsidies that help many new enrollees pay for coverage. In discussing the survey results, Drew Altman, President and CEO of the Kaiser Family Foundation, said, “Most were uninsured because insurance was too expensive, or they didn't have access to employer coverage.” 

The Kaiser survey was conducted in April and May of this year, after the close of the first ACA open enrollment period, and included a national sample of 742 purchasers of insurance on the exchanges.