Compared to other academic content areas, educational researchers conduct relatively few empirical studies focused on students' civics knowledge and teachers then have fewer opportunities to learn about research-based practices. A mixed-methods study was undertaken with 326 high school students (n = 52 with disabilities) and 21 social studies and special education teachers. Results indicated 12th-grade students with disabilities scored significantly lower than their peers on a formative assessment of civics knowledge; students with and without disabilities identified school as their primary source of civics knowledge; and interviews with high school special education and social studies teachers revealed several areas for future research and promising practices teachers can use with their students.