The National Association of County and City Health Officials (NACCHO), with support from the Radiation Studies Branch at the Centers for Disease Control and Prevention (CDC), helps to ensure that local health departments (LHDs) are connected to the most up-to-date and relevant radiation preparedness resources and information. This guide highlights practices and resources to help state and local health departments incorporate electronic population monitoring data management systems into their radiation preparedness planning and exercises. The systems highlighted in this guide include the CRC eTool and the RadResponder Population Monitoring Module. The guide contains a step-by-step process for preparing to use each system, when to use each system, installation and set-up, training offerings, and support resources. In addition, the guide also summarizes key planning, exercise, and operational considerations for use of each system.