The Teacher Working Group (Kelompok Kerja Guru/KKG) is a strategic tool for enhancing the competencies of elementary school teachers. However, in practice, this platform has not been fully utilized. Therefore, the researcher sought to develop it by leveraging the potential of a community of practice to create a model that can be effectively used in the field. The objectives of this study are: (1) to analyze the current condition of the KKG, (2) to develop a KKG model that meets the needs, and (3) to analyze the feasibility of a community of practice-based KKG model in elementary schools. This research is a development study (Research and Development) using the 4D model by Thiagarajan, which includes Define, Design, Develop, and Disseminate. The research design flow begins with an analysis of the factual model, followed by the development of a conceptual model, FGD (Focus Group Discussion), limited testing, main field testing, and the formulation of a hypothetical model followed by operational field testing. Data collection for this research and development study was conducted at three levels: preliminary field testing with 10 subjects, main field testing with 30 subjects, and operational field testing with 85 subjects from 30 elementary schools actively implementing the KKG in Rembang Regency. Data collection methods included questionnaires, documentation, and interviews. The results of the study indicate that the factual condition of KKG implementation is neither effective nor efficient, as evidenced by a low average participation rate and activity impact, around 60%. The researcher then conducted analyses using IFAS, EFAS, CPM, GSM, BCG, and QSPM to develop a model that meets the needs. The conceptual model was reviewed in an FGD with education experts and practitioners, resulting in a community of practice-based KKG model. This model underwent limited testing, followed by the first revision, then main field testing, and finally, operational field testing after a second revision. The community of practice-based KKG model demonstrated feasibility with effectiveness at 90%, efficiency at 89.2%, appeal at 94.3%, satisfaction at 91.4%, and teacher performance reaching 96.5%. Pedagogical competence increased to an average of 75.20 from a previous average of 60.21. Professional competence improved from 64.52 to 80.94. T-test results show a significant difference between the pretest and posttest scores, with a difference of 6.792.