Summer offers the opportunity for sustained community engagement through immersions in summer service-learning programs. A group of 16 colleges and universities that sponsor domestic and international summer service initiatives have formed a Summer Service Collaborative (SSC) to enhance preparation, immersion, and follow-up in light of the unique parameters of summer service-learning. SSC members developed a shared assessment rubric and a pre/post-immersion survey for student participants to evaluate what students learn about poverty, diversity, and civic engagement over the course of summer service-learning experiences. Findings suggest three key areas of student learning and indicate that greater length of engagement coupled with reflection elements create perspective transformation on understanding of social justice for participants.