Do individuals respond to cost-sharing subsidies in their selections of marketplace health insurance plans?

The Affordable Care Act (ACA) provides assistance to low-income consumers through both premium subsidies and cost-sharing reductions (CSRs). Low-income consumers' lack of health insurance literacy or information regarding CSRs may lead them to not take-up CSR benefits for which they are eligible. We use administrative data from 2014 to 2016 on roughly 22 million health insurance plan choices of low-income individuals enrolled in ACA Marketplace coverage to assess whether they behave in a manner consistent with being aware of the availability of CSRs. We take advantage of discontinuous changes in the schedule of CSR benefits to show that consumers are highly sensitive to the value of CSRs when selecting insurance plans and that a very low percentage select dominated plans. These findings suggest that CSR subsidies are salient to consumers and that the program is well designed to account for any lack of health insurance literacy among the low-income population it serves.