The purpose of this study was to describe the methods--including practices, policies, and roles--used by public and academic library staff in a Centers for Disease Control and Prevention (CDC) Racial and Ethnic Approach to Community Health (REACH) intervention that proved successful in reducing or eliminating several diabetes-related health disparities in a vulnerable population. An intrinsic case study methodology was used to identify effective services, resources, and practices for library staff. A semi-structured telephone interview was completed by 11 community partners from a successful multi-partnered, community-based, diabetes-related health disparities intervention that included librarians as community partners. Questions included (a) What were some traditional or innovative library roles, services, or resources used in this successful intervention? (b) How was helicopter research avoided? (c) How was trust with the vulnerable community members established and maintained? (d) How were community members with low literacy included? Data were audio-recorded and transcribed. Eight major themes consistent with transformative adult learning theories were identified from the coded transcripts, including (a) autonomy, (b) community-based and community-led, (c) incentives, (d) a new role for professionals, (e) participants realizing success, (f) church participation, (g) transformation, and (h) perspective of the librarians. The insights and guidelines suggested by this research may be helpful when deciding how or when to participate in community-based health disparities interventions for vulnerable populations. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]