Because the ACA gave them choices in how to implement insurance coverage, health reform looks different state to state. 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 developed by researchers at the University of Pennsylvania that documents and codes state-level variation in the political setting, institutional structures, and operational decisions likely to affect outcomes on the marketplaces.