Quality improvement (QI) interventions in health care organizations have produced mixed results with significant questions remaining about how QI interventions are implemented. Team-based reflection may be an important element for understanding QI implementation. Extensive research has focused on individual benefits of reflection including links between reflection, learning, and change. There are currently no published studies that explore how team-based reflection impact QI interventions. We selected 4 primary care practices participating in a QI trial that used a facilitated, team-based approach to improve colorectal cancer screening rates. Trained facilitators met with a team of practice members for up to eleven 1-hour meetings. Data include audio-recorded team meetings and associated fieldnotes. We used a template approach to code transcribed data and an immersion/crystallization technique to identify patterns and themes. Three types of team-based reflection and how each mattered for QI implementation were identified: organizational reflection promoted buy-in, motivation, and feelings of inspiration; process reflection enhanced team problem solving and change management; and relational reflection enhanced discussions of relational dynamics necessary to implement desired QI changes. If QI interventions seek to make changes where collaboration and coordination of care is required, then deliberately integrating team-based reflection into interventions can provide opportunities to facilitate change processes.