Are adults benefiting from state coverage expansions?

This study provides a rigorous evaluation of state efforts to expand insurance coverage in California, Massachusetts, New Jersey, and Wisconsin. Overall, parents in Wisconsin and parents and childless adults in Massachusetts experienced the largest expansions in public coverage, with few, if any, offsetting reductions in private coverage. In contrast, the coverage expansions for parents in California and New Jersey led to increased enrollment, but often at the expense of private coverage. Because constraints on state resources are putting pressure on expansion efforts, we find evidence that cutbacks will place more adults at risk of being uninsured.