The purpose of the case study was to explore the effects of a mentor-coach initiative among second, third, fourth, and fifth grade teachers in an urban junior-secondary school in Antigua and Barbuda. The case study design was appropriate, mainly qualitative, but supported by quantitative data collection methods. Twelve participants shared in two teams, providing data from journal reflections, questionnaire, and interviews, supporting content and descriptive analyses. From the content analysis, several themes including support, transfer of learning, and hindrances emerged, matched by descriptive statistical analysis results. Collegial support in a transformed professional learning community fostered transfer of learning, improving teacher confidence, hope, competence in planning and instruction, increasing student participation, and enhancing class environment. Involvement in the initiative influenced teachers to plan and apply varied experiential learning strategies, incorporating direct and indirect instruction, meeting or exceeding expectation (≥3.00), and with high percentage (75%) student involvement in every class. The teachers perceived collegial support by mentors positively (3.5) compared to peer coaches (2.3). Participants saw value in the experience, but hindrances influenced the implementation of the mentor-coach initiative negatively, affecting the collaboration in the school community. The results of the research provided background information to start discussion on a government school-based teacher professional development (TPD) policy. Similar research focusing on the peer mentoring-coaching of the principals and teachers in the learning community augurs well for staff development and improved school culture.