Programs offered by universities and other entities outside the organizational boundaries of schools are an important source of ideas and support for educational improvement. Such organizations can focus on important needs-such as improving teaching of science-that schools perhaps cannot address on their own due to resource constraints. In such cases, teacher leaders can play key roles in bringing the knowledge and insights from external organizations into schools, sharing them with colleagues, and gaining administrative support. This kind of teacher leadership, responding to external initiatives rather than just to administrative priorities, is understudied, but programs in Maine that connect schools to universities and nonprofit organizations provide insight into the nature of such teacher leadership. We draw upon cases from two of these programs to offer suggestions to other organizations that might wish to develop programs for teacher leaders in support of educational improvement.