This document provides guidance to help decrease the spread of flu among students and school staff during the 2009-2010 school year. It provides tools that school and health officials can choose from based on conditions in their area and recommends actions to take if CDC finds that the flu starts causing more severe disease. The guidance also provides a checklist for making decisions at the local level. Detailed information on the reasons for these strategies and suggestions on how to use them is included in the Technical Report, available at www.cdc.gov/h1n1flu/schools. [This article was condensed from a report by the Centers for Disease Control and Prevention, August 2009. The complete technical report is available at www.cdc.gov/h1n1flu/schools.]