PROJECT SUMMARY To facilitate the RCMAR mission and goals, we propose the Community Liaison and Recruitment Core (CLRC). Headed by two leaders in the field of community engaged research, Drs. Linda B. Cottler and Janice L. Krieger, the UF CLRC will provide infrastructure that supports the recruitment and community engagement needs of RCMAR scientists as well as contribute to scholarly understanding of what processes are most effective for engaging diverse stakeholder groups. The CLRC will focus strategically on several key areas including recruitment and retention of participants and expanding the knowledge base of clinicians and other scientists who are utilizing the resources of the RCMAR—all centered on bi-directional trust in research and researchers. The recruitment and retention of participants has been called the “greatest obstacle” to treatment developments among older adults. Participants who differ by race, ethnicity, sex, educational level, socioeconomic status, and other social and behavioral factors are urgently needed to make research applicable to all populations. The identification of barriers and facilitators to participation, and then to retention, are critical for successful study completion. The UF CLRC will utilize the research strengths of two disciplines: epidemiology and communication science. Investigators and staff with the CLRC, with decades of experience recruiting and retaining diverse community members for and in research, propose to improve recruitment and retention of populations underrepresented in research. Working hand in hand with the REC, the Admin Core, and the Analysis Core, the CLRC will provide mentoring and support for disseminating findings of the studies through our innovative national town hall meeting, Our Community Our Health, as well as through other communication channels. The CLRC will build upon an Integrated Model of Trust which has been used to explain trust with cancer clinical trials. We intend to focus our efforts on a framework of building relationships that reduce barriers and facilitate best practices that allow the UF RCMAR to contribute to the science of recruitment, retention, and communication science. To do this, the CLRC will: 1) Recruit and enroll 5,000 older adults into a community research registry using interpersonal and mediated strategies and track effort required to recruit different demographic groups (e.g., minorities, rural residents); 2) Generate new knowledge of recruitment and retention strategies that increase trust and give everyone a voice in the research enterprise, comparing the effectiveness of varying models of engagement; and 3) Disseminate best practices of engagement through the CLRC, the REC, and national network of RCMAR Centers to advance the science of community engagement.