Abstract The Intervention Wheel is a population-based practice model that encompasses three levels of practice (community, systems, and individual/family) and 17 public health interventions. Each intervention and practice level contributes to improving population health. The Intervention Wheel, previously known as the Public Health Intervention Model, was originally introduced in 1998 by the Minnesota Department of Health, Section of Public Health Nursing (PHN). The model has been widely disseminated and used throughout the United States since that time. The evidence supporting the Intervention Wheel was recently subjected to a rigorous critique by regional and national experts. This critical process, which involved hundreds of public health nurses, resulted in a more robust Intervention Wheel and established the validity of the model. The critique also produced basic steps and best practices for each of the 17 interventions. Part I describes the Intervention Wheel, defines population-based practice, and details the recommended modifications and validation process. Part II provides examples of the innovative ways that the Intervention Wheel is being used in public health/PHN practice, education, and administration. The two articles provide a foundation and vision for population-based PHN practice and direction for improving population health.