Legally defined geographic areas used in the ACS are updated on an annual basis from a variety of programs, including: the Boundary and Annexation Survey (BAS), the Redistricting Data Program and the School District Review Program.

Summary Level	Geographic Area	Vintage of Geographic Area for 2023 ACS Estimate Year
040	State and State Equivalent	January 1, 2023
050	County or equivalent (Alaska boroughs, Louisana parishes, Puerto Rico municipios, independent cities)	January 1, 2023

County Subdivision
067	Township, Minor Civil Division (MCD)/Barrio and Barrio-Pueblo	January 1, 2023

Place
160	Incorporated Place	January 1, 2023

American Indian/Alaska Native/Hawaiian Home Land
230	Alaska Native Regional Corporations (ANRCs)	January 1, 2023
250/252/254	Federal American Indian Reservation (federal AIR)	January 1, 2023
250/252	State American Indian Reservation (state AIR)	January 1, 2023
251	American Indian Tribal Subdivision, federal AIR	January 1, 2023
250/254	Hawaiian Home Land (HHL)	January 1, 2023

Other Legal Areas
500	Congressional District, Delegate District DC, Resident Commissioner District PR	118th Congress of the United States^/1
610/620	State Legislative Districts (Upper and Lower Chambers)	2022 Legislative Session Year^/1
950/960/970	School District (Elementary, Secondary, Unified)	January 1, 2023
170	Consolidated City	January 1, 2023

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 2023 ACS Estimate Year
050	County Equivalent (Census Areas in Alaska)	January 1, 2023

County Subdivision
060	Census County Division (CCD)	January 1, 2023

Place
160	Census Designated Place (CDP)/Zona Urbana and Comunidad	Janaury 1, 2023

American Indian/Alaska Native/Hawaiian Home Land
250/252	Tribal Designated Statistical Area (TDSA)	2020 Census
250/252	State Designated Tribal Statistical Area (SDTSA)	2020 Census
250/252	Oklahoma Tribal Statistical Area (OTSA)	2020 Census
251	American Indian Tribal Subdivision (within OTSA)	2020 Census
256	Tribal Tract	2020 Census^/2
258	Tribal Block Group	2020 Census^/2
250/252	Alaska Native Village Statistical Area (ANVSA)	2020 Census

Other Statistical Areas
310	Metropolitan Statistical Area/Micropolitan Statistical Area	July 21, 2023^/3/4
312	Metropolitan Statistical Area/Micropolitan Statistical Area - Principal City	July 21, 2023^/3/4
400	Urban Area	2020 Census
140	Census Tract	2020 Census^/2
150	Census Block Group	2020 Census^/2
795	Public Use Microdata Area (PUMA)	2020 Census
860	5-digit ZIP Code Tabulation Area (ZCTA)	2020 Census

^/1The U.S. Census Bureau collects congressional and state legislative districts every two years through the Redistricting Data Program. Typically, new geography products are generated only when changes to congressional or state legislative districts are reported between sessions. For more information see: Redistricting Data Program.

^/2Changes to the boundaries of legal areas may cause complementary changes to the boundaries of selected statistical areas.

^/³While 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.

^/4The 2023 ACS data products for Core Based Statistical Areas (CBSAs), also referred to as Metropolitan and Micropolitan Statistical Areas, are based on post-2020 Census revised delineations published by the Office of Management and Budget (OMB) on July 21, 2023 (OMB Bulletin No. 23-01). For more information see: Metropolitan and Micropolitan.

* NECTA Geographies have been discontinued starting with the 2023 ACS data release. For more information visit 2023 Geography Changes.