Evaluative research for questions of program sustainability has expanded substantially in recent years, but definitional issues remain. This paper presents definitions for four different types of sustainability as potential outcomes of health programs. We then illustrate these definitions with descriptive findings from an on-line survey to "look back" at the extent and types of sustainability that occurred among 48 community-based projects that had received short-term funding from a foundation-funded health program in New Jersey. We found that large percentages of respondents reported positively to each of four types of sustainability measures-maintaining program activities, continuing to serve substantial numbers of clients, building and sustaining collaborative structures, and maintaining attention to the ideas underlying the projects by disseminating them to others. Strengths and limitations of this methodology for future evaluation are also discussed.