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.

2017

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.

Summary Level	Geographic Area	Vintage of Geographic Area for 2017 ACS Estimate Year
040	State and State Equivalent	January 1, 2017
050	County or equivalent (Alaska boroughs, Louisiana parishes, Puerto Rico municipios, independent cities)	January 1, 2017
County Subdivision
067	Minor Civil Division (MCD)/Barrio and Barrio-Pueblo	January 1, 2017
Place
160	Incorporated Place	January 1, 2017
American Indian/Alaska Native/Hawaiian Home Land
230	Alaska Native Regional Corporations (ANRCs)	2010 Census
250/252/254	Federal American Indian Reservation (federal AIR)	January 1, 2017
250/252	State American Indian Reservation (state AIR)	2010 Census
251	American Indian Tribal Subdivision, federal AIR	January 1, 2017
250/254	Hawaiian Home Land (HHL)	2010 Census
Other Legal Areas
500	Congressional District, Delegate District DC, Resident Commissioner District PR	January 1, 2017¹
610/620	State Legislative Districts (Upper and Lower Chambers)	2016 Legislative Session Year
950/960/970	School District (Elementary, Secondary, Unified)^*	2015-2016, January 1, 2016
170	Consolidated City	January 1, 2017

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

¹115th 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.

Summary Level	Geographic Area	Vintage of Geographic Area for 2017 ACS Estimate Year
050	County Equivalent (Census Areas in Alaska)	January 1, 2017
County Subdivision
060	Census County Division (CCD)	2010 Census**
Place
160	Census Designated Place (CDP)/Zona Urbana and Comunidad	2010 Census**
American Indian/Alaska Native/Hawaiian Home Land
250/252	Tribal Designated Statistical Area (TDSA)	2010 Census
250/252	State Designated Tribal Statistical Area (SDTSA)	2010 Census
250/252	Oklahoma Tribal Statistical Area (OTSA)	2010 Census
251	American Indian Tribal Subdivision (within OTSA)	2010 Census
256	Tribal Tract	2010 Census**
258	Tribal Block Group	2010 Census**
250/252	Alaska Native Village Statistical Area (ANVSA)	2010 Census
Other Statistical Areas
310	Metropolitan Statistical Area/Micropolitan Statistical Area	July 15, 2015
312	Metropolitan Statistical Area/Micropolitan Statistical Area - Principal City	July 15, 2015*
350	New England City and Town Area (NECTA)	July 15, 2015
352	New England City and Town Area - Principal City	July 15, 2015*
400	Urban Area	2010 Census
140	Census Tract	2010 Census**
150	Census Block Group	2010 Census**
795	Public Use Microdata Area (PUMA)	2010 Census
860	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.

**Changes to the boundaries of legal areas may cause complementary changes to the boundaries of selected statistical areas.