Chester County
Pennsylvania · County seat: West Chester · Active county or equivalent
FIPS code 42029 is Chester County, Pennsylvania. With a population of 536,474 (2022 ACS estimate), it ranks #7 in Pennsylvania and #129 nationally. Chester County is part of the Philadelphia-Camden-Wilmington, PA-NJ-DE-MD. The state FIPS code for Pennsylvania is 42. This code is used in Census Bureau, BLS, EPA, HUD, and USDA federal datasets to identify this county.
County FIPS
42029
Population
536,474
2022 ACS · #129 nationally
Density
714.8/mi²
people per sq mile
Land Area
751
sq miles
Urban/Rural
Metro — 1M+ population
RUCC 1
How This FIPS Code Works
The 5-digit FIPS code 42029 is formed by combining the 2-digit state identifier 42 (Pennsylvania) with the 3-digit county identifier 029. Together they uniquely identify Chester County in every US federal dataset. No two counties share the same 5-digit FIPS code.
Census ACS Data for FIPS 42029
From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 42029.
Median Household Income
$118,574
ACS B19013_001E
Poverty Rate
6.0%
ACS B17001 (below poverty level)
Median Age
40.7
ACS B01002_001E
Metropolitan Area
Adjacent Counties (6)
Counties that share a border with Chester County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 42029.
Federal Datasets Using Code 42029
FIPS code 42029 appears as the county identifier in the following federal datasets. Analysts joining data across these sources use this code as the common geographic key.
Using FIPS Code 42029 in Code
Common patterns for querying federal datasets by this county's FIPS code. The leading zeros are significant — always treat FIPS codes as strings, not integers.
import requests
url = "https://api.census.gov/data/2022/acs/acs5"
params = {
"get": "NAME,B19013_001E,B01003_001E",
"for": "county:029",
"in": "state:42",
"key": "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json() # [[header...], [Chester County, Pennsylvania, income, pop, ...]-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '42029';
-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '42'
AND county_fips = '029';
-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 42029 is WRONG for this countylibrary(tidycensus)
get_acs(
geography = "county",
variables = c(income = "B19013_001E", pop = "B01003_001E"),
state = "42",
county = "029",
year = 2022
)ZIP Codes in Chester County
ZIP codes do not align perfectly with county boundaries — a single ZIP code can span multiple counties, and a county can contain parts of many ZIP codes. The ratios below (from the Census 2020 ZCTA relationship file) show the land area share of each ZCTA that falls within Chester County. Why FIPS ≠ ZIP →
| ZIP Code | % in county |
|---|---|
| 19369 | 100.0% |
| 19475 | 100.0% |
| 19465 | 100.0% |
| 19457 | 100.0% |
| 19301 | 100.0% |
| 19442 | 100.0% |
| 19311 | 100.0% |
| 19425 | 100.0% |
| 19316 | 100.0% |
| 19390 | 100.0% |
| 19383 | 100.0% |
| 19320 | 100.0% |
| 19330 | 100.0% |
| 19333 | 100.0% |
| 19335 | 100.0% |
| 19341 | 100.0% |
| 19380 | 100.0% |
| 19343 | 100.0% |
| 19375 | 100.0% |
| 19345 | 100.0% |
| 19348 | 100.0% |
| 19350 | 100.0% |
| 19352 | 100.0% |
| 19355 | 100.0% |
| 19358 | 100.0% |
| 19374 | 100.0% |
| 19372 | 100.0% |
| 19365 | 100.0% |
| 19367 | 100.0% |
| 19382 | 97.4% |
Showing top 30 of 46 ZIP codes by residential address share.