The implementation of social workers has been widespread in public defender offices across the U.S. since the 1970s. Yet, we lack research on how social worker programs influence the quality of public defense services provided and the case outcomes of their clients. In this brief, we begin to fill this gap by evaluating the implementation of the Social Worker Defender Program, a social worker program that was developed and pilot tested in one Michigan county’s assigned counsel system. Through case file reviews and interviews with court actors and program participants, we found that a social worker’s presence is beneficial to both court actors and clients of assigned counsel attorneys. We hope this study’s results inform the field about efforts to design and implement social worker programs in assigned counsel systems and embolden more jurisdictions to use similarly innovative strategies to enhance public defense representation.