This article focuses on the quantitative phase of a multiphase mixed methods study investigating adults' and families' access to government food assistance. The research evaluates participants' comprehension of, and ability to, adequately complete authentic complex texts--national food assistance application documents. Summative usability testing of the Supplemental Nutrition Assistance Program application was conducted with 12 adult participants in divergent literacy learning subgroups: 6 adults enrolled in adult literacy classes and 6 adults enrolled in a doctoral program in education. Protocol analysis and extended think alouds were used to evaluate the materials. Individual sessions were audio/video recorded and types, kinds, and rates of error metrics were compared by subgroup. The completion rate without critical errors for doctoral and adult literacy students was 66.6% and 0%, respectively. Results indicate significant concerns with the usability and comprehensibility of food assistance applications and point to the importance of including educationally/linguistically diverse participants in the usability/evaluation process for government assistance applications to prevent further marginalization.