The objective of this application is to design, implement and evaluate an inquiry-based after school science mentorship program for middle school youth, grades five to seven, developed in partnership with and located at the Robert R. McCormick Boys and Girls Club of Chicago. Our long-range goal is to address issues of youth disengagement, minority under-representation, and poor scientific literacy by designing and supporting educational programs that engage youth in the challenge, promise, and wonder of biomedical science. The importance of developing new, effective approaches for biomedical science engagement is underscored by the need to nurture and grow the diversity and quality of America's scientific and health-care enterprise, and to provide all American youth with the scientific and evidence-based analysis skills they require to be informed members of a 21st century democracy. In addition, the applicant addresses the important need to identify the factors that underlie effective after school science programs by measuring specific outcomes like science achievement, attitudes, and career directions and aspirations. In addition, we will provide insight into the personal and professional motivations that lead scientists to engage in science outreach activities- and whether or not participating in outreach during the early stages of training can influence scientists' longer-term attitudes and engagement in outreach. Specifically, we aim to: 1) Develop a mentorship-based model for community-centered youth biomedical science engagement using mentors who are scientists in training, 2) Select, tailor, and implement a set of six themed, inquiry-based biomedical science activities leveraging existing NIH- and NSF-funded projects and supported by field trips, science fairs, and scientific writing Opportunities, 3) Develop programmatic and intellectual linkages between the Boys and Girls Club of Chicago, Northwestern University, John T. McCutcheon Elementary School (P/K-8), and other academic partners, and 4) Evaluate, disseminate, and expand the model of community-based outreach. In addition to addressing the acute need for youth- and adult-based biomedical science engagement, it is our expectation that our community- and mentor-based approach will serve as a model for future science engagement programs involving middle school youth, their families, and academic-community partnerships.