Public Health Authority An agency or authority of the United States, a State, a territory, a political subdivision of a State or territory, or an Indian tribe, or a person or entity acting under a grant of authority from or contract with such public agency, including the employees or agents of such public agency or its contractors or persons or entities to whom it has granted authority, that is responsible for public health matters as part of its official mandate. Legislation Files Containing This Term: legislation/45CFR-164.501.html legislation/45CFR-164.502.html legislation/45CFR-164.512.html