There are 3,244 counties and county equivalents in the United States.^[1][2][a] The 50 states of theUnited States are divided into 3,007 political subdivisions of states calledcounties.^[3] Two hundred thirty-seven other local governments and geographic places are also first-order administrative divisions of their respective state/district/territory, but are not called counties. TheUnited States Census Bureau refers to the latter ascounty equivalents. The 237 county equivalents include theDistrict of Columbia and 100 equivalents inU.S. territories (such as those inPuerto Rico). The large majority of counties and equivalents were organized by 1970. Since that time, most creations, boundary changes and dissolutions have occurred inAlaska,Virginia, andConnecticut.^[2]

Among the 50 states, 44 are partitioned entirely into counties, with no county equivalents.Louisiana is instead divided into 64 equivalentparishes, whileAlaska is divided into19 equivalent boroughs and 11 sparsely populated census areas, the latter also known collectively as theunorganized borough.Virginia is composed of amixture of 95 counties and 38independent cities.Maryland,Missouri andNevada are each composed entirely of counties, except that each also has exactly one independent city:Baltimore,St. Louis, andCarson City, respectively. The District of Columbia is a single federal district that is not part of any state or county. All of the above 136 exceptional cases are reckoned as county equivalents. The number of counties (or equivalents) per state ranges from the three counties ofDelaware, to the 254 counties ofTexas. InNew England, where thetown model predominates, several counties have no corresponding local governments, existing only as historical, legal, and census boundaries, such as the counties ofRhode Island,^[4] as well as eight ofMassachusetts' 14 counties.^[5] On June 6, 2022, the U.S. Census Bureau formally recognizedConnecticut's nine councils of government as county equivalents instead of the state's eight counties.Connecticut's eight historical counties continue to exist in name only, and are no longer considered for statistical purposes.^[6] In total, the 50 states consist of 3,144 counties and equivalents.

Similarly, the Census Bureau treats 100 subdivisions of theterritories of the United States as county equivalents. These are the78 municipalities ofPuerto Rico, thethree major islands of theU.S. Virgin Islands, thethree districts and two atolls ofAmerican Samoa,^[b]Guam as a single island and county equivalent, thefour municipalities of theNorthern Mariana Islands, and the nine island territories of theU.S. Minor Outlying Islands.^[7][8] As in the states, each territorial county equivalent has its ownINCITS/FIPS codes.^[9]

The following table lists the 3,244counties andcounty equivalents of the United States with the following information for each entity:

1. The county or equivalent
2. Thestate or equivalent (federal district orterritory)
3. The population as of April 1, 2020 as enumerated by the US Census Bureau^[10]
4. The county's area in square miles
5. The county's date of foundation