Summer youth employment programs (SYEPs) have the potential to serve as critical bridges to promising careers, especially for young people who hail from disadvantaged backgrounds or reside in underserved areas. Summer jobs can provide early exposure to professional environments, equipping participants with essential skills for the workplace, including communication, teamwork, and problem-solving. However, there is still much to learn about what makes these programs most effective, underscoring a need for funders, policymakers, and practitioners to identify and share best practices for meaningful summer employment experiences. Common challenges include the limited duration of summer, constrained program budgets, difficulties establishing employer engagement, and obstacles to collaboration with schools. As part of an evaluation of a JPMorganChase philanthropic effort to support SYEPs throughout the United States, MDRC conducted over 30 interviews with staff members at grantee programs in 2023 and 2024. This brief is the synthesis of those conversations as well as 13 interviews with policy experts, along with a literature review. This work represents a practitioner-informed understanding of the practices that are believed to improve youth outcomes in this understudied field.