FIPS code 18161 is Union County, Indiana. With a population of 7,041 (2022 ACS estimate), it ranks #91 in Indiana and #2723 nationally. The state FIPS code for Indiana is 18. This code is used in Census Bureau, BLS, EPA, HUD, and USDA federal datasets to identify this county.
County FIPS
18161
Population
7,041
2022 ACS · #2723 nationally
Density
43.7/mi²
people per sq mile
Land Area
161
sq miles
Urban/Rural
Nonmetro — rural, adjacent to metro
RUCC 8
How This FIPS Code Works
The 5-digit FIPS code 18161 is formed by combining the 2-digit state identifier 18 (Indiana) with the 3-digit county identifier 161. Together they uniquely identify Union County in every US federal dataset. No two counties share the same 5-digit FIPS code.
Census ACS Data for FIPS 18161
From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 18161.
Median Household Income
$68,514
ACS B19013_001E
Poverty Rate
6.0%
ACS B17001 (below poverty level)
Median Age
44.5
ACS B01002_001E
Adjacent Counties (5)
Counties that share a border with Union County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 18161.
Federal Datasets Using Code 18161
FIPS code 18161 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 18161 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:161",
"in": "state:18",
"key": "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json() # [[header...], [Union County, Indiana, income, pop, ...]-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '18161';
-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '18'
AND county_fips = '161';
-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 18161 is WRONG for this countylibrary(tidycensus)
get_acs(
geography = "county",
variables = c(income = "B19013_001E", pop = "B01003_001E"),
state = "18",
county = "161",
year = 2022
)ZIP Codes in Union 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 Union County. Why FIPS ≠ ZIP →
| ZIP Code | % in county |
|---|---|
| 47353 | 99.7% |
| 47003 | 96.5% |
| 47325 | 70.8% |
| 47010 | 9.4% |
| 47331 | 3.2% |
| 47374 | 1.2% |