The ACS typically publishes estimates using the latest available geographic boundaries (also known as "vintages"). For ACS 5-year estimates, use the last year of the estimate period to determine the vintage. For example, the following datasets use the same vintages of geographic boundaries:

2022 ACS 1-year estimates
2018-2022 ACS 5-year estimates

To learn more about geographic concepts used in the ACS, check out our geographic handbook Geography and the American Community Survey: What Data Users Need to Know.

2015

Legal Areas
Statistical Areas

Legal Areas

The Census Bureau annually conducts the Boundary and Annexation Survey (BAS) to collect information about selected legally defined geographic areas.

Geographic Area	Vintage of Geographic Area for 2015 ACS Estimate Year
State and State Equivalent	January 1, 2015
County or equivalent (Alaska boroughs, Louisiana parishes, Puerto Rico municipios, independent cities)	January 1, 2015
County Subdivision
Minor Civil Division (MCD)/Barrio and Barrio-Pueblo	January 1, 2015
Place
Incorporated Place	January 1, 2015
American Indian/Alaska Native/Hawaiian Home Land
Alaska Native Regional Corporations (ANRCs)	2010 Census
Federal American Indian Reservation (federal AIR)	January 1, 2015
State American Indian Reservation (state AIR)	2010 Census
American Indian Tribal Subdivision, federal AIR	January 1, 2015
Hawaiian Home Land (HHL)	2010 Census
Other Legal Areas
Congressional District, Delegate District DC, Resident Commissioner District PR	January 1, 2015¹
State Legislative Districts (Upper and Lower Chambers)	2014 Legislative Session Year
School District (Elementary, Secondary, Unified)^*	2013-2014, January 1, 2014
Consolidated City	January 1, 2015

*School district boundaries are updated every two years as part of the School District Review Program.

¹114th Congress of the United States

Statistical Areas

For statistical areas, boundary changes are mostly associated with updates from each decennial census. Statistical areas are designed to have stable boundaries over time.

Geographic Area	Vintage of Geographic Area for 2015 ACS Estimate Year
County Equivalent (Census Areas in Alaska)	January 1, 2015
County Subdivision
Census County Division (CCD)	2010 Census
Place
Census Designated Place (CDP)/Zona Urbana and Comunidad	2010 Census
American Indian/Alaska Native/Hawaiian Home Land
Tribal Designated Statistical Area (TDSA)	2010 Census
State Designated Tribal Statistical Area (SDTSA)	2010 Census
Oklahoma Tribal Statistical Area (OTSA)	2010 Census
American Indian Tribal Subdivision, OTSA	2010 Census
Tribal Tract	2010 Census
Tribal Block Group	2010 Census
Alaska Native Village Statistical Area (ANVSA)	2010 Census
Other Statistical Areas
Metropolitan Statistical Area/Micropolitan Statistical Area	February 28, 2013
Metropolitan Statistical Area/Micropolitan Statistical Area - Principal City	February 28, 2013*
New England City and Town Area (NECTA)	February 28, 2013
New England City and Town Area - Principal city	February 28, 2013*
Urban Area	2010 Census
Census Tract	2010 Census
Census Block Group	2010 Census
Public Use Microdata Area (PUMA)	2010 Census
5-digit ZIP Code Tabulation Area (ZCTA)	2010 Census

^*While the American Community Survey (ACS) data generally reflect the Office of Management and Budget (OMB) definitions of metropolitan and micropolitan statistical areas; in certain instances the names, codes, and boundaries of the principal cities shown in ACS tables may differ from the OMB definitions due to differences in the effective dates of the geographic entities.