The United States Assistant Secretary for Health (ASH) serves as the Secretary of Health and Human Services's primary advisor on matters involving the nation's public health and, if serving as an active member in the regular corps, is the highest ranking uniformed officer in the Public Health Service Commissioned Corps (PHSCC). The ASH oversees all matters pertaining to the Public Health Service (PHS), the main division of the Department of Health and Human Services (HHS), for the Secretary as well as provide strategic and policy direction for the PHSCC. The PHS comprises almost all the agency divisions of the HHS as well as the PHSCC, a uniformed service of more than 6,000 health professionals who serve at the HHS, other federal agencies, and/or are assigned details to the armed forces. The ASH is a civilian or a uniformed member of the regular corps and is nominated for appointment by the President. The nominee must also be confirmed via majority vote by the Senate. The ASH serves a four-year term of office at the pleasure of the President. If the appointee is a serving member of the regular corps, he or she is also appointed as a four-star admiral in the regular corps  . The President may also nominate a civilian appointee to also be appointed a commission in the regular corps if the nominee so chooses. As such the position of ASH is the only office in the PHS that merits a four-star grade in the regular corps. The current Assistant Secretary for Health is Dr. Howard K. Koh.
The Office of the Assistant Secretary for Health and Scientific Affairs was established on January 1, 1967 following the Reorganization Plan No. 3 of 1966. The plan allowed the Secretary of Health, Education, and Welfare to restructure the Public Health Service to better serve public health. The office was renamed to the Office of the Assistant Secretary for Health following the Department of Education Organization Act in 1972.
The stars, shoulder boards, and sleeve stripes of the Assistant Secretary for Health if serving in the U.S. Public Health Service Commissioned Corps.