Description

IPUMS USA cannot identify most counties in recent samples.

COUNTYFIP identifies the county where the household was enumerated, using the Federal Information Processing Standard (FIPS) coding scheme.

COUNTYFIP codes are state-dependent; they must be combined with state codes (see STATEFIP or STATEICP) to distinguish counties located in different states.

Many county boundaries and some county names have changed over time. IPUMS does not impose a uniform county boundary system on the data, so each county listed for a given year in IPUMS should be assumed to have the boundaries that it had in that year.

Counties are not identified in public-use microdata from 1950 onwards, so IPUMS instead identifies counties, where possible, from other low-level geographic identifiers. These include State Economic Areas (SEA) in 1950; county groups in 1970 (CNTYGP97) and 1980 (CNTYGP98); and Public Use Microdata Areas (PUMA) from 1990 onwards, including Super-PUMAs (PUMASUPR) in 2000.

In 1950 and later samples, COUNTYFIP identifies a county if and only if:

• it was coterminous with a single SEA, county group, or PUMA; or

• it contained multiple SEAs, county groups, or PUMAs, none of which extended into other counties.

• Identified Counties, 1950-Forward

For municipios, the Puerto Rican statistical equivalent of U.S. counties, see PRCOUNTA (alphabetic version) and PRCOUNTY (numeric version).

FIPS codes were first instituted around the time of the 1970 census, so historical counties that were dissolved before then have no FIPS code. COUNTYICP and COUNTYNHG supply codes for the complete history of U.S. county definitions. These alternative variables both use codes based on the 3-digit FIPS scheme with a fourth digit added to distinguish historical counties.

Like STATEFIP, COUNTYFIP facilitates merging IPUMS data with data from other sources that use FIPS codes.

COUNTYFIP is a 3-digit numeric variable that identifies the county where the household was enumerated using the Federal Information Processing Standard (FIPS) coding scheme.

COUNTYFIP codes are state-dependent; they must be combined with state codes (see STATEFIP or STATEICP) to distinguish counties located in different states.

COUNTYFIP codes differ from standard FIPS codes in one case: Dade County, Florida, had FIPS code 025 until its name was changed to Miami-Dade County in 1997, with a new FIPS code of 086. COUNTYFIP assigns a code of 086 to Dade County in all samples to be consistent with the Miami-Dade code in later samples.

COUNTYFIP-Specific Variable Code
000 = County not identifiable from public-use data (1950-onward)

List of counties identified in 1950 and later samples:

• Identified Counties, 1950-Forward

Comparability

This variable is comparable across years, but county boundaries change over time. For more information about changes to counties, see the Census Bureau’s page on Substantial Changes to Counties and County Equivalent Entities: 1970-Present.

It is worth noting that the Census Bureau changed the statistical units for Connecticut from ‘counties’ to the county-equivalent unit, ‘planning regions’, starting with the 2022 ACS. Connecticut counties identified in COUNTYFIP for the 2022 ACS and forward are these new planning regions identified by the Census Bureau.

Universe

Availability

• 2022: All samples
• 2021: All samples
• 2020: All samples
• 2019: All samples
• 2018: All samples
• 2017: All samples
• 2016: All samples
• 2015: All samples
• 2014: All samples
• 2013: All samples
• 2012: All samples
• 2011: All samples
• 2010: All samples
• 2009: All samples
• 2008: All samples
• 2007: All samples
• 2006: All samples
• 2005: All samples
• 2004: --
• 2003: --
• 2002: --
• 2001: --
• 2000: 5%; 1% old; 1% unwt; 1%
• 1990: 5% state; 1% metro; 1% unwt
• 1980: 5% state; 1% metro
• 1970: 1% metro fm1; 1% metro fm2
• 1960: 5%
• 1950: All samples
• 1940: --
• 1930: --
• 1920: --
• 1910: --
• 1900: --
• 1880: --
• 1870: --
• 1860: --
• 1850: --

• 2022: --
• 2021: --
• 2020: --
• 2019: --
• 2018: --
• 2017: --
• 2016: --
• 2015: --
• 2014: --
• 2013: --
• 2012: --
• 2011: --
• 2010: --
• 2009: --
• 2008: --
• 2007: --
• 2006: --
• 2005: --
• 2000: --
• 1990: --
• 1980: --
• 1970: --
• 1930: --
• 1920: --
• 1910: --

Flags

Editing Procedure

There is no editing procedure available for this variable.