Purpose: Civic education is a central mission of public schools, and deeper learning of civics--learning that is complex and adaptive--is the goal. However, assessment of deeper civic learning is limited. Therefore, we aimed to develop an assessment model and test of deeper learning in the common high school civics course taught across the U.S. Design/methodology/approach: Using Design-Based Implementation Research (DBIR), the assessment model and test were iteratively researched and revised by a team of researchers and teachers across seven years and multiple settings. Findings: Results of validity and reliability studies show that the model and test are promising tools for assessing deeper civic learning. Research limitations/implications: Additional research is warranted to refine the test-development process, design alternative test forms, and adapt the model to other social studies courses. Practical implications: We suggest ways to use this assessment model to assess learning in civics and other social studies subjects.