The states are divided into smaller administrative regions, called counties in all but two states. In Alaska, the county equivalents are called boroughs, and in Louisiana, the county equivalents are called parishes. Counties have varying degrees of political and legal significance. In some states, mainly in New England, they are primarily used as judicial districts. In other states, counties have broad powers in housing, education, transportation and recreation. As of 2018, there are currently 3,242 counties in the 50 states and the District of Columbia.

Wszystkie stany USA (z wyjątkiem Alaski i Luizjany) dzielą się na hrabstwa (ang. county), których jest 3048.