A guide to understanding the variation in premiums in rural health insurance marketplaces.

Key Findings. (1) State-level decisions in implementing the Patient Protection and Affordable Care Act of 2010 (ACA) have led to significant state variation in the design of Health Insurance Marketplace (HIM) rating areas. In some designs, rural counties are grouped together, while in others, rural and urban counties have been deliberately mixed. (2) Urban counties have, on average, approximately one more firm participating in the marketplaces, representing about 11 more plan offerings, than rural counties have. (3) The highest-valued "platinum" plan types are less likely to be available in rural areas. Thus, the overall mix of plan types should be factored into the reporting of average premiums. (4) Levels of competition are likely to have a greater impact on the decisions of firms considering whether to operate in higher-cost areas or not, as those firms must determine how they can pass such costs on to consumers, conditional on the market share they are likely to control.