The U.S. Department of Health and Human Services contracted RAND to develop resources and prepare analyses that help describe and enhance key aspects of state and local public health emergency preparedness. As part of this work, RAND designed and tested a new quality-improvement tool that public health agencies can adopt to regularly look back at each routine annual influenza season to systematically institutionalize knowledge from one influenza season to the next; continuously improve the public health response to routine annual influenza; and incorporate lessons into preparedness activities for pandemic influenza and other public health emergencies. RAND staff developed and pilot-tested this “Look-Back” methodology in three state public health agencies (SPHAs) in different regions of the United States between June and August 2005.