The success of efforts to improve student outcomes in precollege mathematics at community colleges hinges on engaging and supporting non-tenure-track faculty [NTTF], who comprise a significant proportion of precollege instructional staff. Although research suggests weak departmental support and barriers and constraints to NTTF engagement, no studies have focused specifically on NTTF in the context of precollege mathematics reform in community colleges. This qualitative case study fills a gap in our understanding through interviews with seven tenure-track faculty [TTF] and 11 NTTF from three departments participating in the Washington State Rethinking Pre-College Mathematics grant. The case study examines the nature and effectiveness of strategies and incentives developed by TTF to engage their NTTF peers in department-led reform of precollege mathematics. Each department was successful in securing NTTF engagement across a broad spectrum, using strategies that included offering perquisites, professional development, and targeted instructional support. The NTTF detailed some changes in their practice, such as diversifying classroom instruction and approaches to assessment. Strategies that successfully initiated engagement (e.g., compensation) differed from those that sustained engagement, with the latter leveraging NTTF interest in growing professionally in order to improve student outcomes and build professional relationships with peers. Findings inform the delivery of NTTF professional development by suggesting that education and training expand beyond the delivery of new content to include relationship building with other faculty. The study's findings also consider NTTF professional development to be a shared responsibility among departments, colleges, systems, and NTTF.