docs/us_demographics/demographics_geographic_classification_county

demographics_geographic_classification_county

Federal geographic classification, one row per US county (A6). metro_status (central_metro/outlying_metro/micropolitan/noncore_rural) and the cbsa_* fields come from the OMB 2023 CBSA delineation; rucc_code (1-9) from USDA ERS Rural-Urban Continuum Codes 2023. nchs_urb_rural_code is a DERIVED 6-level approximation of the NCHS 2013 Urban-Rural scheme computed from OMB + RUCC — NOT the published NCHS file; the large-central vs large-fringe split is proxied from OMB central/outlying. Fully populated for all 3,222 counties including Connecticut's 2022 planning regions. Tier A.

tier aothermetrourbanruralsuburbancbsaruccurbanicityclassificationgeography
grain
county
years
2023
cadence
OMB CBSA: irregular (every 5-10 years); USDA RUCC: every 10 years; NCHS: every 10 years
overview

overview

All 3,222 US counties. Loaded from OMB CBSA delineations, USDA RUCC, and NCHS urban-rural classification.

current vintage — OMB CBSA: 2023; USDA RUCC: 2023; NCHS: 2013

history — OMB CBSA: 2003, 2013, 2018, 2020, 2023; USDA RUCC: 1974, 1983, 1993, 2003, 2013, 2023

provenance

source & licensing

authority
U.S. Office of Management and Budget|U.S. Department of Agriculture (Economic Research Service)
dataset
OMB CBSA Delineation 2023 + USDA ERS Rural-Urban Continuum Codes 2023
license
Public domain (U.S. federal government work)
citation
Office of Management and Budget. Bulletin 23-01: Revised Delineations of Metropolitan Statistical Areas (2023); USDA ERS, Rural-Urban Continuum Codes (2023); NCHS Urban-Rural Classification Scheme for Counties (2013).
schema

fields

nametypedefinition
cbsa_central_outlyingstringIndicates whether the county is the 'Central' or 'Outlying' county of its CBSA per the OMB 2023 delineation. NULL for noncore counties.
cbsa_codestring5-character OMB Core-Based Statistical Area code identifying the metro or micropolitan area containing the county. NULL for noncore (non-CBSA) counties.Joins dim.cbsas on cbsa_code.
cbsa_titlestringOfficial OMB CBSA title for the area containing the county (e.g. 'Los Angeles-Long Beach-Anaheim, CA'). NULL for noncore counties.
country_idkeystringISO alpha-2 country code (always 'US' for domestic tables).Part of primary key.
county_idkeystring5-character FIPS code identifying the county.Part of primary key. Joins dim.counties on county_id.
county_namestringHuman-readable county name corresponding to county_id.
csa_codestring3-character OMB Combined Statistical Area code, present where the county's CBSA is part of a larger CSA. NULL where the CBSA does not belong to a CSA or the county is noncore.
metro_statusstringOMB 2023 CBSA-based metropolitan classification: 'central_metro' or 'outlying_metro' (county is the central or outlying county of a Metropolitan Statistical Area), 'micropolitan' (in a Micropolitan Statistical Area), or 'noncore_rural' (not in any CBSA).
nchs_urb_rural_codeint64DERIVED approximation of the NCHS 2013 6-level Urban-Rural Classification (1 = Large central metro … 6 = Noncore), computed from OMB metro_status and USDA RUCC rather than the published NCHS file. The large-central vs large-fringe distinction is proxied from the OMB central/outlying designation. Lower values indicate more urban counties.
nchs_urb_rural_descriptionstringHuman-readable label for the derived nchs_urb_rural_code (e.g. 'Large central metro', 'Noncore').
rucc_codeint64USDA ERS Rural-Urban Continuum Code (2023 edition), an integer 1–9. Metro codes 1–3 are ordered by metro-area population size; nonmetro codes 4–9 are ordered by urbanization level and adjacency to a metro area. Lower values indicate more urban, more populous counties.
rucc_descriptionstringHuman-readable label for the rucc_code category (e.g. 'Metro - Counties in metro areas of 1 million population or more').
state_idkeystring2-character FIPS code identifying the state.Part of primary key. Joins dim.states on state_id.
relationships

joins

primary key
county_id, state_id, country_id
common joins
dim.geographies on county_id
demographics_population_county_year for population context
usage

how to use this table

method

OMB CBSA assigns counties to metropolitan/micropolitan statistical areas based on commuting patterns from decennial census. USDA RUCC classifies counties on 1-9 scale by population and metro adjacency. NCHS classifies counties on 6-level urban-rural typology.

do not use for

Sub-county urban/rural classification (use Census urban areas); current-year boundaries when CBSA delineations have changed.

known issues

CBSA delineations change every few years - rural-to-metro transitions create discontinuities in any time series.

last updated · Jul 7, 2026