With the approaching launch of the second open enrollment period for the Affordable Care Act’s (ACA) health insurance marketplaces and at a time when open enrollment is also happening for many job-based plans, the Kaiser Family Foundation conducted a nationally representative survey of 1,292 U.S. adults to shed light on Americans’ understanding of basic health insurance terms and concepts, and to identify gaps in awareness that could lead to difficulties for some individuals as they choose new plans or use their health plans.