While service-learning has distinguished itself in the literature as a problem-based experiential alternative to dominant classroom-based, subject-centered pedagogies, there is a strange absence of research based on program planning theory. This work introduces program planning theory to the field of service-learning and reports findings from a comparative analysis of service-learning case studies that led to the development of a relational model for understanding program planning theory and incorporating it in service-learning research and practice. (Contains 2 notes, 2 tables, and 1 figure.)