The threat of an influenza pandemic has been at the forefront of public health preparedness for more than 5 years. The national planning effort has included stockpiling antiviral drugs in the Centers for Disease Control and Prevention's Strategic National Stockpile (SNS). This article highlights the composition of the SNS before the 2009 H1N1 pandemic and includes considerations for future antiviral stockpile purchases, focusing on emergence of oseltamivir resistance and the need for additional pediatric supplies.