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Geographic Terms and Concepts - County Subdivision

County Subdivisions are the primary divisions of counties and equivalent entities.  They include census county divisions, census subareas, minor civil divisions, and unorganized territories and can be classified as either legal or statistical.  Each county subdivision is assigned a five-character numeric Federal Information Processing Series (FIPS) code based on alphabetical sequence within state and an eight-digit National Standard feature identifier.

Legal Entities

Minor civil divisions (MCDs) are the primary governmental or administrative divisions of a county in many states (parishes in Louisiana) and the county equivalents in Puerto Rico and the Island Areas.  MCDs in the United States, Puerto Rico, and the Island Areas represent many different kinds of legal entities with a wide variety of governmental and/or administrative functions.  MCDs include areas variously designated as barrios, barrios-pueblo, boroughs, charter townships, commissioner districts, election districts, election precincts, gores, grants, locations, magisterial districts, parish governing authority districts, plantations, purchases, reservations, supervisor's districts, towns, and townships.  The Census Bureau recognizes MCDs in 29 states, Puerto Rico, and the Island Areas.  The District of Columbia has no primary divisions and is considered equivalent to an MCD for statistical purposes.  (It is also considered a state equivalent and a county equivalent.) The 29* states in which MCDs are recognized are:

Arkansas Michigan Ohio
Connecticut Minnesota Pennsylvania
Illinois Mississippi Rhode Island
Indiana Missouri South Dakota
Iowa Nebraska Tennessee
Kansas New Hampshire Vermont
Louisiana New Jersey Virginia
Maine New York West Virginia
Maryland North Carolina Wisconsin
Massachusetts North Dakota  
* Tennessee, a state with statistical census county divisions (CCDs) in 2000, reverted to MCDs in 2008.

In some states, all or some incorporated places are not part of any MCD; these places are termed independent places.  Independent places also serve as primary legal subdivisions and have a Federal Information Processing Series (FIPS) county subdivision code and National Standard (ANSI) code that is the same as the FIPS and ANSI place code.  In nine states—Maine, Massachusetts, New Hampshire, New Jersey, North Dakota, Pennsylvania, Rhode Island, South Dakota, and Wisconsin—all incorporated places are independent places.  In other states, incorporated places are part of, or dependent within, the MCDs in which they are located, or the pattern is mixed—some incorporated places are independent of MCDs and others are included within one or more MCDs.

The MCDs in 12 states (Connecticut, Maine, Massachusetts, Michigan, Minnesota, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, and Wisconsin) also serve as general-purpose local governments that can perform the same governmental functions as incorporated places.  The Census Bureau presents data for these MCDs in all data products for which place data are provided.

In New York and Maine, American Indian reservations (AIRs) generally exist outside the jurisdiction of any town (MCD) and thus also serve as the equivalent of MCDs for purposes of data presentation.

In states with MCDs, the Census Bureau assigns a default FIPS county subdivision code of 00000 and ANSI code of eight zeroes in some coastal, territorial sea, and Great Lakes water where county subdivisions do not legally extend into the Great Lakes or out to the 3-mile limit.

Statistical Entities

Census county divisions (CCDs) are areas delineated by the Census Bureau in cooperation with state, tribal, and local officials for statistical purposes.  CCDs have no legal function and are not governmental units.  CCD boundaries usually follow visible features and usually coincide with census tract boundaries.  The name of each CCD is based on a place, county, or well-known local name that identifies its location.  CCDs exist where:

  1. There are no legally established MCDs.
  2. The legally established MCDs do not have governmental or administrative purposes.
  3. The boundaries of the MCDs change frequently.
  4. The MCDs are not generally known to the public.

CCDs exist within the following 20* states:

Alabama Hawaii Oregon
Arizona Idaho South Carolina
California Kentucky Texas
Colorado Montana Utah
Delaware Nevada Washington
Florida New Mexico Wyoming
Georgia Oklahoma  
* Tennessee, a CCD state in 2000, reverted to a MCD state in 2008.

Census subareas are statistical subdivisions of boroughs, city and boroughs, municipalities, and census areas, all of which are statistical equivalent entities for counties in Alaska.  The state of Alaska and the Census Bureau cooperatively delineate the census subareas to serve as the statistical equivalents of MCDs.

Unorganized territories (UTs) are defined by the Census Bureau in nine MCD states where portions of counties or equivalent entities are not included in any legally established MCD or incorporated place.  The Census Bureau recognizes such separate pieces of territory as one or more separate county subdivisions for census purposes.  It assigns each unorganized territory a descriptive name, followed by the designation "UT" and a county subdivision FIPS and ANSI code.  The following states have unorganized territories:

Arkansas Maine North Carolina
Indiana Minnesota North Dakota
Iowa New York South Dakota

Source: U.S. Census Bureau | Geography | (301) 763-1128 |  Last Revised: December 06, 2012