This dataset was created to help users to go between County - State Name, State-County FIPS, City, or to ZIP Code. Most importantly, this dataset was created because we shouldn't have to pay for free & public data.

Assumptions - HUD uses the most up to date Zip Code boundaries from the USPS when they post their new Quarterly data. *ZIP Codes are updated on a regular basis. Here is an example announcement from the USPS. - City data only available from 2018 onward.

Data Sources

US HUD https://www.huduser.gov/portal/datasets/usps.html

Census Bureau The table data, direct link. This data is only updated once every census, 10 years. The details of the National County text file can be found here

USPS Zip to City Lookup More information can be found here. It's a free API from the USPS. Need to create a username to pull the data.

Data Dictionary

Files 2018 -> Newer - ZIP ZIP Code - STCOUNTFP US State & County FIPS ID - CITY City for that Zip/Fips Code - STATE US State - COUNTYNAME US County Name - CLASSFP FIPS Class Code, as defined by the Census

Files 2010-2017 - ZIP ZIP Code - COUNTYNAME US County Name - STATE US State - STCOUNTFP US State & County FIPS ID - CLASSFP FIPS Class Code, as defined by the Census

FIPS Class Code Details Source Copied 7/29/17

• H1 identifies an active county or statistically equivalent entity that does not qualify under subclass C7 or H6.
• H4 identifies a legally defined inactive or nonfunctioning county or statistically equivalent entity that does not qualify under subclass H6.
• H5 identifies census areas in Alaska, a statistical county equivalent entity.
• H6 identifies a county or statistically equivalent entity that is a really coextensive or governmentally consolidated with an incorporated place, part of an incorporated place, or a consolidated city.
• C7 identifies an incorporated place that is an independent city; that is, it also serves as a county equivalent because it is not part of any county, and a minor civil division (MCD) equivalent because it is not part of any MCD.

Acknowlegement

Foto von Annie Spratt auf Unsplash

Abstract

A crosswalk dataset matching US ZIP codes to corresponding county codes

Documentation

The denominators used to calculate the address ratios are the ZIP code totals. When a ZIP is split by any of the other geographies, that ZIP code is duplicated in the crosswalk file.

**Example: **ZIP code 03870 is split by two different Census tracts, 33015066000 and 33015071000, which appear in the tract column. The ratio of residential addresses in the first ZIP-Tract record to the total number of residential addresses in the ZIP code is .0042 (.42%). The remaining residential addresses in that ZIP (99.58%) fall into the second ZIP-Tract record.

So, for example, if one wanted to allocate data from ZIP code 03870 to each Census tract located in that ZIP code, one would multiply the number of observations in the ZIP code by the residential ratio for each tract associated with that ZIP code.

https://redivis.com/fileUploads/4ecb405e-f533-4a5b-8286-11e56bb93368%3E" alt="">(Note that the sum of each ratio column for each distinct ZIP code may not always equal 1.00 (or 100%) due to rounding issues.)

County definition

In the United States, a county is an administrative or political subdivision of a state that consists of a geographic region with specific boundaries and usually some level of governmental authority. The term "county" is used in 48 U.S. states, while Louisiana and Alaska have functionally equivalent subdivisions called parishes and boroughs, respectively.

Further reading

The following article demonstrates how to more effectively use the U.S. Department of Housing and Urban Development (HUD) United States Postal Service ZIP Code Crosswalk Files when working with disparate geographies.

Wilson, Ron and Din, Alexander, 2018. “Understanding and Enhancing the U.S. Department of Housing and Urban Development’s ZIP Code Crosswalk Files,” Cityscape: A Journal of Policy Development and Research, Volume 20 Number 2, 277 – 294. URL: https://www.huduser.gov/portal/periodicals/cityscpe/vol20num2/ch16.pdf

Contact information

Questions regarding these crosswalk files can be directed to Alex Din with the subject line HUD-Crosswalks.

Acknowledgement

This dataset is taken from the U.S. Department of Housing and Urban Development (HUD) office: https://www.huduser.gov/portal/datasets/usps_crosswalk.html#codebook

Analysis of ‘US Zipcodes to County State to FIPS Crosswalk’ provided by Analyst-2 (analyst-2.ai), based on source dataset retrieved from https://www.kaggle.com/danofer/zipcodes-county-fips-crosswalk on 28 January 2022.

--- Dataset description provided by original source is as follows ---

Context

Dataset created to link between County - State Name, State-County FIPS, and ZIP Code.

Acknowledgements

Data Sources

• US HUD

https://www.huduser.gov/portal/datasets/usps.html

• Census Bureau

https://www2.census.gov/geo/docs/reference/codes/files/national_county.txt https://www.census.gov/geo/reference/codes/cou.html

Data cleaned by Data4Democracy and hosted originally on Data.World: https://github.com/Data4Democracy/zip-code-to-county https://data.world/niccolley/us-zipcode-to-county-state

ZCTA data from USPS 6.2017 release.

Image from Reddit.

--- Original source retains full ownership of the source dataset ---