The Home Support Exercise Program (HSEP) was developed to reach frail community seniors through home support workers (HSWs) rather than more costly health care professionals such as visiting nurses or physical therapists. This article describes the development and formative evaluation of the HSEP prototype, including the training of case managers and HSWs. In the HSEP’s final form, each client is instructed on 10 simple, functional, and progressive exercises and given an illustrated booklet and a short video. Ongoing encouragement is provided by specifically trained HSWs during regular visits (at least once a week). Formative evaluation of the HSEP model was used to examine and resolve implementation and delivery issues. Qualitative data were collected through focus groups or interviews with each stakeholder group—administrators/coordinators, case managers, HSWs, agency supervisors, and clients themselves. Evaluation findings were used to modify training, instructional, and support materials and the exercises.