Anthem is a master-planned community partially located within Phoenix and partially located within a census-designated place. The community is entirely located in Maricopa County, Arizona, United St…Anthem is a master-planned community partially located within Phoenix and partially located within a census-designated place. The community is entirely located in Maricopa County, Arizona, United States, within the Phoenix Metropolitan Area. As of the 2020 census, the population of the Anthem CDP was 23,190.