As districts and schools struggle with persistent teacher shortages, many states have attempted to bolster the supply of teachers by loosening credentialing requirements or implementing fast-track programs that quickly bring new teachers into the classroom, often without student teaching or robust coursework about how to teach. Some states, including California, have taken a different approach, launching new teacher preparation models called teacher residencies that subsidize and support high-quality preparation for teaching in high-need shortage areas. As a result of the expansion of teacher residencies within the California landscape, there is an opportunity to examine examples of successful residencies to understand how they operate. In a series of case studies, the authors examined five of the state's most effective programs, as indicated by graduates and their employers: (1) the Alder Graduate School of Education Master's and Credential Teacher Residency Program; (2) Claremont Graduate University Teacher Education Program; (3) Kern Urban Teacher Residency at California State University, Bakersfield; (4) Teacher Residency for Rural Education at California State University, Bakersfield; and (5) Tri-County Teacher Residency Program at California State University, Monterey Bay. This report includes program descriptions and cross-case findings related to key program characteristics that are commonly found in effective residencies, plus additional programming considerations that emerged from the case studies. After the discussions of characteristics and findings, the report describes ongoing challenges experienced in the case study programs, followed by a summary of findings and recommendations for sustaining and strengthening residencies, both at the program level and through state and federal policies.