The history of NACCHO dates to the 1960s, with the formation of the National Association of County Health Officials (NACHO), an independent affiliate of the National Association of Counties. NACHO combined with the U.S. Conference of Local Health Officers, an organization affiliated with the
United States Conference of Mayors, to form the National Association of County and City Health Officials (NACCHO) in 1994. This unified organization represents
counties,
cities,
city-counties,
districts, and
townships governmental local health departments. In 2001, NACCHO expanded its scope to include tribal public health agencies for reservation lands and, in 2012, to include counties and cities in the
U.S. territories. As of 2020, NACCHO has about 2,800
local health departments. ==Governance==