Purpose: This paper aims to describe experience gained with a required six-credit year-long course, the Capstone Interdisciplinary Team Project, a key component of the Master of Science (MS) in Sustainability degree at the City College of New York. A common feature of sustainability problems is their interdisciplinary nature. Solutions to sustainability problems often require professionals with different training and backgrounds to work as a team. A sustainability curriculum should provide students with the skills needed to competently participate in an interdisciplinary team. Design/Methodology/Approach: Instructors drawn from different departments and divisions of the college developed a pool of sustainability-focused Capstone projects and acted as mentors to teams of students with diverse undergraduate backgrounds. Students attended workshops designed to provide training in teamwork, research and report preparation. An independent evaluator designed an evaluation protocol to assess the course's impact both while it was implemented and after the course was concluded. Findings: Early experience with the program strongly indicates that the Capstone project requirement is an effective learning tool. However, identifying qualified mentors, developing suitable projects, assembling teams and administering the Capstone course are demanding tasks. Although students often experience difficulties in the early stages of their work, they ultimately express satisfaction and appreciation for the skills learned in the course. Practical implications: The inclusion of a capstone team project in a graduate sustainability curriculum is strongly recommended. Adopting such a course requires significant effort and sustained faculty engagement. Originality/value: Although there is considerable experience with undergraduate engineering Capstone course requirements, little is known about interdivisional capstone requirements at the level of master's degree in Sustainability. This paper details new and relevant experience helpful to the implementation of such a requirement.