This chapter is built on the premise that science teachers develop their practice along a professional continuum that consists of recruitment, preparation, new teacher induction, ongoing professional development, and advanced certification or master teacher opportunities (NCTAF 1996). The authors argue that science leadership from local districts, state policymakers, and providers of higher education can keep science teachers in the classroom and the larger educational system by providing professional learning opportunities that meet these particular needs. They also propose that by intentionally providing opportunities for teachers who have advanced along the career continuum to interact with early-career teachers, leaders can leverage the knowledge and wisdom of practice of experienced teachers to support the development of beginning teachers.