This chapter describes an evolving professional learning community (PLC) project for science and technology (S&T) teachers in Junior High Schools across Israel. The 5-year (2015–2020) S&T teacher PLC project started with one national leading teachers’ PLC and grew to 22 regional PLCs around Israel. The PLC characteristics were: shared setup and structured process; relations of trust and norms of collaboration; targeted focus on student learning; assessment-based learning and decision-making; and reflective dialogues and inquiry. Two PLC models evolved during the 5 years of this research-based project: a multilevel Collaboration Model of community skills enhancement; and a Network Model of knowledge transmission among S&T PLC participants. Data from questionnaires, interviews, and various meetings indicate that PLC members developed professional profiles that combined aspects such as S&T education proficiencies, a sense of mission, a desire for excellence, passion, commitment, and the motivation to have an impact.