Under its democratically elected civilian government, teacher education in Burma was poised for change. The Burmese Ministry of Education, together with their development partners, had ushered in an era of system-wide education reform. This reform redefined the role of teachers, overhauled how teachers were to be trained and supported, and was on course to installing increased teacher accountability measures across the country. The centerpiece of reform efforts pertaining to educators was the Teacher Competency Standards Framework (TCSF), which was developed through a multi-year process culminating in the publication of robust "beginning level" indicators in 2019. This study evidences the existing competencies of Burmese educators employed in Migrant Learning Centers on the Thai-Burma border through enrollment in a comprehensive in-service teacher - training program, which utilizes the TCSF. Participants (n=132) enrolled in a 10-month teacher-training program based on TeacherFOCUS's Learn-Choose-Use Approach. Overall, participants improved by 15.34% across ten observed and eight knowledge-based teaching competencies when comparing baseline and endline evaluation results. Significantly, teachers exhibited the greatest gains when presented with different options of how they could improve. This study affirms key aspects of teacher professional development that should be considered in low-resource contexts: teacher ownership, transparent accountability measures, place-based instruction and coaching, high-quality feedback and modeling, contextually relevant design, and strong professional relationships.