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Geography Release Notes for 2010

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2010 Census Designated Place, Tract and Block Group Changes

Census Designated Place

Census Designated Places (CDPs) are statistical areas that are redefined every decade through the Census Bureau's Participant Statistical Areas Program or PSAP, in association with the decennial census. The Geography Division published the Geographic Comparability File, 2010 to 2000 Places to assist data users in understanding the differences between the 2010 and 2000 CDP and incorporated place universes.

Geographic Comparability File, 2010 to 2000 Places

CDPs can change in a number of different ways from one decade to the next. Here are some examples of how CDPs can change.

• CDPs can be renamed (Y CDP, AK is now named Susitna North CDP, AK)
• CDPs can change a portion of their geographic definition and still be considered the same CDP (Accokeek CDP, MD)^*
• CDPs can become incorporated places (Braintree CDP, MA is now Braintree Town city, MA)
• CDPs can cease to exist (Green Valley CDP, MD)
• CDPs can split (Suitland-Silver Hill CDP, MD is now Suitland CDP and Silver Hill CDP)
• CDPs can merge (Hazel Dell North CDP and Hazel Dell South CDP merged to form Hazel Dell CDP, WA)
• CDPs can completely change geographic definition, not be considered comparable, but retain the name of a previously defined CDP (Box Elder CDP, MT)
• New CDPs can be defined (Abanda CDP, AL)

* Geographic definition changes are not included in the Geographic Comparability File.

Census Tracts and Block Groups

Census tracts and block groups are redefined each decade through the Census Bureau's Participant Statistical Areas Program or PSAP, in association with the decennial census. Tribal tracts and tribal block groups were defined through a similar program, the Tribal Statistical Areas Program or TSAP. Changes to the definitions of census tracts and block groups between the two censuses can result in tract/block group merges, splits, boundary changes, geographic code changes, or combinations of these. However, not all census tracts and block groups change definitions between censuses.

The Geography Division published the 2010 Census Tract Relationship Files to assist data users in determining the relationships between 2010 Census tracts and Census 2000 tracts. Tribal tracts are not included in the relationship files. The Census Bureau does not publish block group relationship files, but does publish block relationship files.

2010 Census Tract Relationship Files

For more information on PSAP and TSAP, visit:

• Participant Statistical Areas Program Website
• Tribal Statistical Areas Program Website