List of boroughs and census areas in Alaska in the context of "U.S. county"

In the United States, a county or county equivalent is an administrative subdivision of a state or territory, typically with defined geographic boundaries and some level of governmental authority. The term "county" is used in 48 states, while Louisiana and Alaska have functionally equivalent subdivisions called parishes and boroughs, respectively. Counties and other local governments exist as a matter of U.S. state law, so the specific governmental powers of counties may vary widely between the states, with many providing some level of services to civil townships, municipalities, and unincorporated areas. Certain municipalities are in multiple counties. Some municipalities have been consolidated with their county government to form consolidated city-counties or have been legally separated from counties altogether to form independent cities. Conversely, counties in Connecticut and Rhode Island, eight of Massachusetts's 14 counties, and Alaska's Unorganized Borough have no government power, existing only as geographic distinctions.

The United States Census Bureau uses the term "county equivalent" to describe places that are comparable to counties, but called by different names. Louisiana parishes, the organized boroughs of Alaska, independent cities, and the District of Columbia are equivalent to counties for administrative purposes. Alaska's Unorganized Borough is further divided into 11 census areas that are statistically equivalent to counties. In 2024, the U.S. Census Bureau began to also recognize Connecticut's councils of governments, which took over some of the regional powers from the state's former county governments, as county equivalents.

Most U.S. states and territories have at least two tiers of local government: counties and municipalities. Louisiana uses the term parish and Alaska uses the term borough for what the U.S. Census Bureau terms county equivalents in those states. Civil townships or towns are used as subdivisions of a county in 20 states, mostly in the Northeast and Midwest.

Population centers may be organized into incorporated municipalities of several types, including the city, town, borough, and village. The types and nature of these municipal entities are defined by state law, and vary from state to state. In addition to these general-purpose local governments, states may also create special-purpose local governments. Depending on the state, local governments may operate under their own charters or under general law, or a state may have a mix of chartered and general-law local governments. Generally, in a state having both chartered and general-law local governments, the chartered local governments have more local autonomy and home rule. Municipalities are typically subordinate to a county government, with some exceptions. Certain cities, for example, have consolidated with their county government as consolidated city-counties. In Virginia, cities are completely independent from the county in which they would otherwise be a part. In some states, particularly in New England, towns form the primary unit of local government below the state level, in some cases eliminating the need for county government entirely. Many rural areas and even some suburban areas of many states have no municipal government below the county level.

Louisiana (French: Louisiane [lwizjan]; Spanish: Luisiana [lwiˈsjana]; Louisiana Creole: Lwizyàn) is a state in the Deep South and South Central regions of the United States. It borders Texas to the west, Arkansas to the north, and Mississippi to the east. Of the 50 U.S. states, it ranks 31st in area and 25th in population, with roughly 4.6 million residents. Reflecting its French heritage, Louisiana is the only U.S. state with political subdivisions termed parishes, which are equivalent to counties, making it one of only two U.S. states not subdivided into counties (the other being Alaska and its boroughs). Baton Rouge is the state's capital, and New Orleans, a French Louisiana region, is its most populous city with a population of about 363,000 people. Louisiana has a coastline with the Gulf of Mexico to the south; a large part of its eastern boundary is demarcated by the Mississippi River and the mouth of the Mississippi or delta defines much of its lower topography.

Much of Louisiana's lands were formed from sediment washed down the Mississippi River, leaving enormous deltas and vast areas of coastal marsh and swamp. These contain a rich southern biota, including birds such as ibises and egrets, many species of tree frogs—such as the state-recognized American green tree frog—and fish such as sturgeon and paddlefish. More elevated areas, particularly in the north, contain a wide variety of ecosystems such as tallgrass prairie, longleaf pine forest and wet savannas; these support an exceptionally large number of plant species, including many species of terrestrial orchids and carnivorous plants. Over half the state is forested.

In United States local government, a consolidated city-county (see below for alternative terms) is formed when one or more cities and their surrounding county (parish in Louisiana, borough in Alaska) merge into one unified jurisdiction. As such it is a type of unitary authority that has the governmental powers of both a municipal corporation and a county.

A consolidated city-county is different from an independent city, although the latter may result from consolidation of a city and a county and may also have the same powers as a consolidated city-county. An independent city is a city not deemed by its state to be located within the boundary of any county and considered a primary administrative division of its state. A consolidated city-county differs from an independent city in that the city and county both nominally exist, although they have a consolidated government, whereas in an independent city, the county does not even nominally exist. Furthermore, a consolidated city-county may still contain independent municipalities maintaining some governmental powers that did not merge with the rest of the county.

The Unorganized Borough is composed of the portions of the U.S. state of Alaska which are not contained in any of its 19 organized boroughs. While referred to as the "Unorganized Borough", it is not a borough itself, as it forgoes that level of government structure. It encompasses nearly half of Alaska's land area, 323,440 square miles (837,700 km), and, as of the 2020 U.S. census, it had a population of 77,157, which was 10.52% of the population of the state. The largest communities in the Unorganized Borough are the cities of Bethel, Unalaska, and Valdez.

There are 3,244 counties and county equivalents in the United States. The 50 states of the United States are divided into 3,007 political subdivisions of states called counties. 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. The United States Census Bureau refers to the latter as county equivalents. The 237 county equivalents include the District of Columbia and 100 equivalents in U.S. territories (such as those in Puerto Rico). The large majority of counties and equivalents were organized by 1970. Since that time, most creations, boundary changes and dissolutions have occurred in Alaska, Virginia, and Connecticut.

Among the 50 states, 44 are partitioned entirely into counties, with no county equivalents. Louisiana is instead divided into 64 equivalent parishes, while Alaska is divided into 19 equivalent boroughs and 11 sparsely populated census areas, the latter also known collectively as the unorganized borough. Virginia is composed of a mixture of 95 counties and 38 independent cities. Maryland, Missouri and Nevada are each composed entirely of counties, except that each also has exactly one independent city: Baltimore, St. Louis, and Carson 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 of Delaware, to the 254 counties of Texas. In New England, where the town model predominates, several counties have no corresponding local governments, existing only as historical, legal, and census boundaries, such as the counties of Rhode Island, as well as eight of Massachusetts' 14 counties. On June 6, 2022, the U.S. Census Bureau formally recognized Connecticut'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. In total, the 50 states consist of 3,144 counties and equivalents.