“The ACA gave states a number of choices in how to implement the broad coverage changes it required. As such, health reform looks different from state to state, and the impact of the ACA may or may not differ because of these state decisions. This Data Brief examines a number of choices related to the establishment and running of the new health insurance marketplaces, and their potential impact on enrollment rates to date. We use existing data sources as well as a new database, HIX 2.0, which provides a rich array of state-level variables to provide an ongoing picture of ACA implementation. HIX 2.0, developed by researchers at the University of Pennsylvania, documents and codes state-level variation in the political setting, institutional structures, and operational decisions likely to affect outcomes on the marketplaces.”