The current study used a case study methodological approach, including document analysis, semistructured interviews, and participant observations, to investigate how a science, technology, engineering, and mathematics (STEM) enrichment program supported retention and degree attainment of underrepresented students at a large, public, predominantly white institution. From this study, a model emerged that encompassed four components: proactive care, holistic support, community building, and catalysts for STEM identity development. These components encompassed a number of strategies and practices that were instrumental in the outcomes of program participants. This paper concludes with implications for practice, such as using models to inform program planning, assessment, and evaluation.