PACE Center for Girls is a Florida-based nonprofit organization that serves girls of middle school and high school age who are at risk of involvement with the justice system. PACE aims to get these girls back on track by taking a gender-responsive approach, providing a blend of academic and social services that are shaped by an awareness of girls' particular development and gender-specific needs. Since its founding in 1985, PACE has been committed to being a learning organization: It has adjusted its services over time to align with emerging research, partnered with MDRC to evaluate the implementation and impact of its day program, and consistently used the findings to launch improvements. Findings from the evaluation add to the body of knowledge about how gender-responsive principles can be implemented in different contexts to engage girls who are at risk. PACE's partnership with MDRC and its improvement efforts also offer lessons for how researchers and practitioners can work together to produce rigorous and actionable evidence in the social sector and actively translate evidence into practice to refine and improve interventions.