From 2001 to early 2005, Osterholm served as a Special Advisor to then–Department of Health and Human Services (HSS) Secretary Tommy G. Thompson on issues related to bioterrorism and public health preparedness. In April 2002, he was appointed to the interim management team to lead the Centers for Disease Control and Prevention (CDC), until the appointment of Julie Gerberding as director in July 2002. Thompson asked Osterholm to assist Gerberding on his behalf during the transition period. He filled that role through January 2003. In 2005, HHS Secretary Mike Leavitt appointed Osterholm to the National Science Advisory Board on Biosecurity.