In 2002, the federal government established the Strategic National Stockpile (SNS), a pharmaceutical and vaccine stockpile, jointly managed by the Department of Homeland Security (DHS) and the Department of Health and Human Services (HHS), to provide for public health emergencies. The SNS extended earlier stockpile programs for use in case of chemical, biological, radiological or nuclear attack. In 2006, Congress funded the addition of protective equipment to the stockpile, adding 52 million surgical masks and 104 million N95 respirator masks. That legislation assigned to the HHS Assistant Secretary for Preparedness and Response (ASPR), responsibility for coordination of the stockpile for the Secretary of HHS. During the spring 2009 H1N1 pandemic, much of the mask stockpile was depleted .
Holdren, John P., Christine Cassel, Chris Chyba, Susan Graham, Eric Lander, Ed Penhoet, William Press, Maxine Savitz, and Harold Varmus. "Recommendations for the National Strategic Pandemic Stockpile." May 2020.