Recently, a renewed interest in large-scale community health worker (CHW) programs has been seen globally. This renewal provides an opportune moment to take stock of issues and challenges such programs face and what can be done to make them as effective as possible. With this in mind, this manual is intended to be used a practical guide for policymakers and program managers wishing to develop or strengthen a CHW program, drawing lessons from other countries that have implemented CHW programs at-scale. Throughout, we discuss major policy and programmatic issues that decision-makers and planners need to consider when designing, implementing, scaling up or strengthening a national-level CHW program. We offer an overview of specific challenges CHW programs face, country lessons, tools, and other resources that may be helpful, while incorporating relevant programmatic examples as much as possible.