This study examines the nature of the interaction of banks and community development financial institutions (CDFIs) in small business lending. We examine the experience of six different CDFIs that vary by size, corporate structure, and market. We explore how they both collaborate and compete with regulated lenders, and how changes in local and national market dynamics affect their activities. Our case studies are not necessarily representative of the CDFI industry, but they offer insights on the factors that shape CDFIs' interactions with and responses to more mainstream institutions. Our findings are therefore more descriptive than prescriptive, although we offer suggestions for both CDFI practice and future research.