The article describes a methodology for organizing lifelong learning, professional retraining of teachers in STEM field and their lifelong learning in Volodymyr Hnatiuk Ternopil National Pedagogical University (Ukraine). It analyzes foreign and domestic approaches and concepts for the implementation of STEM in educational institutions. A model of retraining teachers in the prospect of developing their STEM competencies and a model of STEM competencies were created. The developed model of STEM competencies for professional teacher training and lifelong learning includes four components (Problem solving, Working with people, Work with technology, Work with organizational system), which are divided into three domains of STEM competencies: Skills, Knowledge, Work activities. In order to implement and adapt the model of STEM competencies to the practice of the educational process, an experimental study was conducted. The article describes the content of the scientific research and the circle of respondents and analyzes the results of the research
