In September 2015, just before the third open enrollment period of the Affordable Care Act's (ACA) Health Insurance Marketplace was about to open, we surveyed insured Texans ages 18 to 64 to assess their confidence level in understanding the basic terminology about health insurance plans and in how they use their health insurance plans. Our data show that, as compared to Texans with employer-sponsored insurance (ESI) and those with public health insurance, Texans with individual plans were more likely to lack confidence in understanding health insurance terminology. Texans with individual plans also expressed more difficulty in understanding how to use their health insurance plans.