Developing interventions to improve engagement in mental health treatment brings researchers to the most basic questions: Who participates in mental health care? How can we promote participation in care? Does good participation lead to better outcomes? Research on engagement seeks to address these fundamental questions with interventions designed to improve both participation and the clinical impact of care. This month Interian and colleagues review interventions to improve engagement of persons from underserved racial-ethnic minority groups. The importance of their work and the need for research to improve engagement cannot be overstated. Engagement may not be sufficient, but it is necessary—without engagement we cannot achieve successful clinical outcomes.