This toolkit serves as a resource for local public health departments to develop plans for medical mass care. The toolkit provides scalable, operational direction and tools for the establishment of alternative care sites, i.e. Influenza Care Centers (ICC) to meet the health care needs of patients requiring hospital care who are not able to receive such care at one of the local hospitals. Although the guide focuses on pandemic influenza, the approaches described and the tools provided can be adapted for other medical-health emergencies and hazards requiring medical mass care.