Increased accountability in education has brought renewed emphasis on the assurance of learning, making certain that students meet specified learning objectives. Additional research has focused on ways individuals learn. Building upon research on learning styles, active learning, and team-based learning (TBL), this study assesses the impact of TBL on students' preferred learning styles. Using the Grasha-Riechmann Learning Styles Survey, the study shows that students' preference for Independent, Collaborative, and Participant learning styles increased significantly over the course of a semester in classes using TBL.