It was only over a decade ago that data on dismal learning outcomes in low- and middle-income countries (LMICs) shook the international education field out of its complacency with rising enrollment rates. The organizations and researchers that led this protest catalyzed a global shift toward prioritizing effective learning as the ultimate goal of education. However, acts of protest or disruption occur in a single point in time, whereas the transformations they advocate for are the labor of many years. Such is the case of the call to action to address the learning crisis. In the past decade, donor agencies like USAID have partnered with ministries of education in LMICs to design and implement programs at scale based on evidence of what works to improve foundational skills. A recent retrospective on the past ten years of USAID early grade reading programming (EnCompass LLC & MCI [2021]. Ten Years of USAID Early Grade Reading Programming: A Retrospective) estimates that USAID programs have improved reading outcomes for more than 7 million children and acknowledges tangible progress in the agency and its partners’ understanding of effective early reading instruction. The study also found that despite significant accomplishments, even the best-designed programs were hindered in their effectiveness by factors related to education systems’ low capacity to implement best practices at scale. Similarly, the Learning at Scale study, funded by the Bill & Melinda Gates Foundation, is examining some of the most effective large-scale early learning programs of the last ten years to understand the elements of their success. Learning at Scale researchers point out that improving learning at scale is hard because it usually requires working through the complex realities of government systems. Therefore, while the first chapter of the “learning crusade” yielded important lessons on what works to improve learning, there is still a lot to be learned about how to apply this knowledge to build effective government systems that ensure learning for all children. Case in point are government systems for continuous teacher professional development (TPD). It is well-known that better teaching is one of the fundamental interventions for improved learning outcomes. There is also a growing evidence base on the characteristics of effective TPD programs, as curated through initiatives like Learning at Scale and The Science of Teaching, also funded by the Gates Foundation. Among these characteristics are trainings that emphasize practice over theory and coaching programs based on structured coaching tools and frequent interaction with teachers. Another teacher support element that can be important to program success is school-based teacher communities-of-practice, which enable peer-to-peer feedback and opportunities to reflect on the ongoing application of instructional approaches. Both Learning at Scale and the retrospective study on USAID early reading programming observe a trend toward shorter but more frequent teacher training events that take place at the local level, in contrast to the massive national trainings of the past. The use of online content for teacher training is also on the rise, though preliminary findings from Learning at Scale suggest that an initial face-to-face training event continues to be essential. However, being able to identify the ingredients of effective teacher support does not automatically equate with an understanding of how to build a continuous TPD system that incorporates them. Neither does it mean that a TPD system built entirely on evidence-based best practices is guaranteed to succeed in improving learning outcomes. As more LMICs advance toward instituting standards and structured career ladders for the teaching profession, and toward developing mechanisms to increase the equity and efficiency of teacher training and support, it becomes increasingly important to identify effective models for implementing continuous TPD at scale. the panel will feature a USAID program in Jordan that exemplifies the desired result: a national-scale, comprehensive TPD model that is aligned with a broader policy on the teacher career path and is linked to a robust assessment data system that reinforces accountability for learning. It is the only program with solid evidence of positive changes in teaching practices that led to significant improvements in student outcomes.