There is a growing body of educational research that suggests that out-of-school-time experiences for youth may play a larger role in engaging, preparing, inspiring, and creating lifelong interest in science than previously recognized. Studies indicate that many professional scientists trace their initial passion for science to an after school club or extracurricular activity. Others suggest that afterschool settings may be particularly good at making science engaging and promoting science, technology, engineering, and mathematics (STEM) career paths. Just like scientific research, after school experiences have an “unreasonable effectiveness” in celebrating the joy of discovery and beauty of science while also providing practical benefits by inspiring the future STEM workforce. However, most scientists who engage in public education, outreach, and activities for broader impacts still largely focus on classroom experiences and classroom teachers. In this session, we will present the rationale, motivation, promising practices, and case studies of professional scientists and engineers partnering with after school organizations to provide high-quality activities and act as role models for youth. While these settings offer unique opportunities that are less time- and content-constrained than classroom settings, they also offer specific challenges. We will also spend time in small groups considering specific strategies for recruiting and supporting scientists to be successful in out-of-school-time learning settings.