The assistant secretary for health (ASH) is a senior U.S. government official within the United States Department of Health and Human Services (HHS). The position is a statutory office (42 U.S.C. § 202) and the holder of the office serves as the United States Secretary of Health and Human Services's primary advisor on matters involving the nation's public health. The assistant secretary oversees all matters pertaining to the United States Public Health Service (PHS), the main division of the Department of Health and Human Services, for the secretary, and provides strategic and policy direction. The Public Health Service comprises almost all of the agency divisions of the Department of Health and Human Services including the United States Public Health Service Commissioned Corps, one of the