Community health workers (CHWs) can help to achieve the goals of the Affordable Care Actbetter health, better care, and lower costs. CHWs are typically laypeople whose close connections with a community enable them to win trust and improve health and health services for those they serve. However, challenges with financing structures, workforce training, and service organization can hinder the expansion of the CHW workforce. This paper highlights the roles played by CHWs, assesses evidence of their achievements, describes the increasing opportunities for them under health care reform, and considers productive next steps for growing the CHW workforce.