Continuing professional development for teachers is an important aspect of innovation and progress in any educational system. In this exploratory position paper, we examine the sole teacher education institution in Singapore as it re-examines its role in transforming teacher professional development. We propose a framework which can be used by Singapore's National Institute of Education to support the sustainable and transformative professional development of science teachers. Placing teachers instead of policy changes at the core of professional development, this framework illustrates how teacher-led inquiry and involvement in communities of practice can be integrated to support continuing professional development so as to impact teachers' practices and ensure the sustainability of professional development.