The Centers for Disease Control and Prevention (CDC) created a health communication marketing and promotion support system (support system) to help 10 CDC-funded national organizations (recipients) grow enrollment of underserved populations in the National Diabetes Prevention Program. This article describes the creation of a successful support system to increase the use of effective marketing approaches and key messaging. The support system was developed using a systematic approach. It included a needs assessment, audience research, marketing strategy identification, expert panel review, materials development, and dissemination guidance. Hands-on, individualized, and group end-user training and technical assistance was also included. Recipients received culturally and linguistically tailored marketing materials to support their specific priority audiences, as well as corresponding training on recommended dissemination methods. In in-depth key-informant interviews, staff from six recipients reported increased knowledge of local communities and audiences, efficacy and skills to conduct media interviews, capacity to identify and train champions and influencers, and greater community partner investments. With marketing support, 90% of recipients reported increased enrollment, of which 40% exceeded self-set targets and another 40% doubled or tripled their enrollment numbers. These findings indicate that a customized strategic health communication marketing and promotion support system presents a significant opportunity to help recipients increase enrollment in evidence-based interventions. Practitioners disseminating evidence-based interventions may consider a support system to increase program uptake.