A census-designated place (CDP) is an area identified by the United States Census Bureau for statistical reporting. CDPs are communities that lack separate municipal government, but which otherwise resemble incorporated places, such as cities or villages. CDPs are delineated to provide data for settled concentrations of population that are identifiable by name but are not legally incorporated under the laws of the state in which they are located. The boundaries are defined in cooperation with local or tribal officials, but are not fixed. CDP boundaries may change from one census to the next to reflect changes in settlement patterns. Further, as statistical entities, the boundaries of the CDP may not precisely correspond with local understanding of the area with the same name.
By defining an area as a CDP, that locality then appears in the same category of census data as incorporated places. This distinguishes CDPs from other census classifications, such as minor civil divisions (MCDs), which are in a separate category.
However, the CDP has no separate town rights or city councils. The population and demographics of the district are included in the data of county subdivisions containing the CDP. In no case is a CDP defined within the boundaries of an incorporated city, village or borough. (However, note that the Census Bureau considers Towns in New England states and New York as well as Townships in some other states as MCDs, even though they may be considered incorporated municipalities in those states).
There are a number of reasons for such a designation:
- The area may be more urban than its surroundings, having a concentration of population with a definite residential nucleus, such as Whitmore Lake, Michigan, or Hershey, Pennsylvania.
- A formerly incorporated place may disincorporate or be partly annexed by a neighboring town, the former town or a part of it may still be reported by the census as a CDP by meeting criteria for a CDP, for example the former village of Covedale, Ohio and compare this with Covedale (CDP), Ohio.
- The CDP designation may apply to large military bases that are not within the boundaries of any existing community, such as Fort Campbell and Fort Knox in Kentucky.
- In some cases, a CDP may be defined for the urbanized area surrounded an incorporated municipality, but which is outside the municipal boundaries, for example Greater Galesburg, Michigan.
- Some CDPs represent an aggregation of several nearby communities, for example Shorewood-Tower Hills-Harbert, Michigan.
- Hawaii is the only state that has no incorporated places recognized by the U.S. Census Bureau below the county level. All data for places in Hawaii reported by the Census are CDPs.
- In some states, CDPs may be defined within entities that may function as incorporporated municipalities, but for the purposes of the census are regarded as minor civil divisions. For example towns in Massachusetts and Connecticut provide all the services of an incorporated municipality, but may also include both rural and urban area. CDPs may be defined to describe urbanized areas within such municipalites, for example, North Amherst, Massachusetts.
- In some states, the Census Bureau may designate an entire minor civil division (MCD) as a CDP (for example West Bloomfield Township, Michigan or Reading, Massachusetts. Such designations are used in states where the MCDs function with strong governmental authority and provide services equivalent to an incorporated municipality (New England, the Middle Atlantic States, Michigan, and Wisconsin). MCDs appear in a separate category in census data from places (i.e., incorporated places and CDPs), however, such MCDs strongly resemble incorporated places and so CDPs that are coterminous with the MCDs are defined so that such places appear in both categories of census data.
The Census Bureau reported data for some unincorporated places as early as the 1850 census, though usage continued to evolve through the 1890 census. The 1900 through 1930 censuses did not report data for unincorporated places. For the 1940 census, the Census Bureau compiled a separate report of unofficial, unincorporated communities of 500 or more people. The Census Bureau officially recognized "unincorporated places" in the 1950 census. For the 1980 census, the designation was changed to "census-designated places". From 1950 through 1990, the Census Bureau had population requirements for unincorporated places or CDPs. This minimum population requirement was dropped with the 2000 census.
- U.S. Census Bureau, Geography Division, "Cartographic Boundary Files (http://www.census.gov/geo/www/cob/pl_metadata.html#cdp)", Census-designated place. Cartographic Operations Branch, July 18, 2001.
- U.S. Census Bureau, "Census 2000 Statistical Areas Boundary Criteria (http://www.census.gov/geo/www/psapage.html#CDP)", Census Designated Places (CDPs) - Census 2000 Criteria.
- U.S. Census Bureau, Chapter 9: Places (http://www.census.gov/geo/www/GARM/Ch9GARM.pdf), Geographic Areas Reference Manual