The U.S. Census Bureau conducts the Boundary and Annexation Survey (BAS) annually to collect information about selected legally defined geographic areas. The BAS is used to update information about the legal boundaries and names of all governmental units in the United States. The Census Bureau uses the boundary information collected in the BAS to tabulate data for the decennial and economic censuses, as well as annual estimates and surveys such as the Population Estimates Program and the American Community Survey.
The Census Bureau mails BAS materials in December of each year to all federally recognized American Indian areas, governmental counties (and equivalent areas), incorporated places, consolidated cities, and governmental Minor Civil Divisions (MCDs).
Responses to the 2010 BAS must be received by the Census Bureau before March 1st, 2010 to be included in the 2010 Census, the Population Estimates Program, the American Community Survey, the final review of the Boundary Validation Program (BVP), and the 2011 BAS.
The links below provide detailed information about the 2010 BAS for participants and other interested parties. Links to other Census Bureau programs and surveys are listed under "Related Program Links".
ScheduleThis link provides a list of key dates in the 2010 BAS.
Response MethodsThis link provides information on ways in which participants can respond to the 2010 BAS.
Materials (forms, letters, postcards, respondent guides) for:
Counties, Minor Civil Division (MCDs), and Places
American Indian Areas
Counties, MCDs, and Places
American Indian Areas
This link provides access to the 2009 BAS maps in PDF format.
2010 BAS MapsAvailable in January 2010.
County Consolidation AgreementsState Certification Boundary Validation Program (BVP) Frequently Asked Questions (FAQs) Data Links
New Incorporations [Excel] [Text]
American Indian Entities and Codes [Excel] [Text]
BAS Entities and Codes [Excel] [Text]
BAS Entities Summarized by State & Type (County, Place, MCD)
American Community Survey
Census Bureau ANSI (formerly FIPS) Page
Census Bureau Geographic Programs
Geographically Updated Population Certification Program (GUPCP)
Population Estimates Program
Special Census Program
Local Update of Census Addresses (LUCA)
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