Going into the Affordable Care Act: Measuring the Size, Structure, and Performance of the Individual and Small Group Markets for Health Insurance

The Affordable Care Act (ACA) will dramatically alter health insurance markets and the sources through which individuals obtain coverage. As the ACA is implemented, it is essential to monitor the intended and the unintended consequences of these regulations. To evaluate the changes in health insurance markets linked to the ACA, it is critical to consistently measure the size and structure of health insurance markets, as well as the performance of participating health insurers, prior to and post-ACA. In this paper we discuss challenges of describing the size, structure, and performance of the individual and small group markets. Next, we discuss improvements in data availability starting in 2010 to address some of these concerns. Finally, using data from the National Association of Insurance Commissioners (NAIC), we evaluate insurance market structure and performance during 2010-2012, focusing on enrollment, the number of participating insurers, premiums, claims spending, MLR, and administrative expenses.