Uzbekistan’s Ministry of Pre-school and School Education (MoPSE) has embarked upon an ambitious reform agenda to bring the Uzbek public education system in line with twenty-first century international standards and skills that includes participating for the first time in the Progress in International Reading Literacy Study (PIRLS) in 2021 and in the Program for International Student Assessment (PISA) in 2022. At the onset of UEEP, the teaching culture in many schools in Uzbekistan was still quite teacher-centric, with only a modicum of observable student-centered instructional strategies promoting critical thinking, creativity, communication, and collaboration. Basic reading and mathematics scores were within the international mean, but students struggled with reading comprehension and more complex mathematics. In 2023 UEEP designed and piloted an evidence-based, in-service, continuous TPD (CTPD) cascade approach that sought to improve classroom instruction for Uzbek Language Arts and Mathematics teachers via the effective implementation of TGs and the student-centered strategies therein. The training approach consisted of a three-tiered cascade training model where 80 Tier 1 Master Trainers (MTs) trained and supported 800 Tier 2 trainers, who in turn trained over 8,000 Tier 3 teachers. Training sessions included evidence-based practical instructional techniques such as modeling, role-playing, small group practice, and discussion. The CTPD approach used Methodological Days (MDs) already existing within the Uzbek education system to conduct the monthly sessions rather than one-off, multi-day training events. The Program provided all trainers with facilitator guides, slides, and scripts. The Program implemented the CTPD approach using three concurrent processes of (1) readiness and training, (2) follow-up and quality assurance, and (3) action research. The Program’s ambitious action research agenda determined the degree to which teachers were applying new techniques and whether the cascade CTPD approach was effective. Specifically, the Program designed and implemented a study to assess the effectiveness of the Program’s CTPD cascade approach in terms of teachers’ satisfaction of learning events, their acquisition of knowledge and skills, their shift in self-efficacy, possible changes in teacher beliefs about new teaching approaches, and to what extent teachers received the necessary support at the administrative and school levels. The CTPD effectiveness study used an adapted version of Kirkpatrick’s training evaluation model2 as the guiding framework. In this panel, we will share the findings of this study which suggest minimal dilution effect between levels of training, and discuss some of the critical success factors, namely, the monthly dosage of trainings and the quality assurance ‘feedforward’ loop that led to the effectiveness of the cascade approach.