Mifflin County
Pennsylvania · County seat: Lewistown · Active county or equivalent
FIPS code 42087 is Mifflin County, Pennsylvania. With a population of 46,146 (2022 ACS estimate), it ranks #46 in Pennsylvania and #1062 nationally. Mifflin County is part of the Lewistown, PA. 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
42087
Population
46,146
2022 ACS · #1062 nationally
Density
112.3/mi²
people per sq mile
Land Area
411
sq miles
Urban/Rural
Nonmetro — urban 20K+, adjacent to metro
RUCC 4
How This FIPS Code Works
The 5-digit FIPS code 42087 is formed by combining the 2-digit state identifier 42 (Pennsylvania) with the 3-digit county identifier 087. Together they uniquely identify Mifflin County in every US federal dataset. No two counties share the same 5-digit FIPS code.
Census ACS Data for FIPS 42087
From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 42087.
Median Household Income
$58,012
ACS B19013_001E
Poverty Rate
16.7%
ACS B17001 (below poverty level)
Median Age
43.3
ACS B01002_001E
Metropolitan Area
Adjacent Counties (5)
Counties that share a border with Mifflin County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 42087.
Federal Datasets Using Code 42087
FIPS code 42087 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 42087 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:087",
"in": "state:42",
"key": "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json() # [[header...], [Mifflin County, Pennsylvania, income, pop, ...]-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '42087';
-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '42'
AND county_fips = '087';
-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 42087 is WRONG for this countylibrary(tidycensus)
get_acs(
geography = "county",
variables = c(income = "B19013_001E", pop = "B01003_001E"),
state = "42",
county = "087",
year = 2022
)ZIP Codes in Mifflin 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 Mifflin County. Why FIPS ≠ ZIP →
| ZIP Code | % in county |
|---|---|
| 17075 | 100.0% |
| 17004 | 100.0% |
| 17009 | 100.0% |
| 17029 | 100.0% |
| 17044 | 100.0% |
| 17051 | 100.0% |
| 17054 | 100.0% |
| 17099 | 100.0% |
| 17084 | 100.0% |
| 17063 | 94.1% |
| 17841 | 53.8% |
| 17002 | 17.7% |
| 17066 | 17.6% |
| 17060 | 7.1% |