Morgan County
Indiana · County seat: Martinsville · Active county or equivalent
FIPS code 18109 is Morgan County, Indiana. With a population of 71,757 (2022 ACS estimate), it ranks #23 in Indiana and #764 nationally. Morgan County is part of the Indianapolis-Carmel-Greenwood, IN. 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
18109
Population
71,757
2022 ACS · #764 nationally
Density
177.6/mi²
people per sq mile
Land Area
404
sq miles
Urban/Rural
Metro — 1M+ population
RUCC 1
How This FIPS Code Works
The 5-digit FIPS code 18109 is formed by combining the 2-digit state identifier 18 (Indiana) with the 3-digit county identifier 109. Together they uniquely identify Morgan County in every US federal dataset. No two counties share the same 5-digit FIPS code.
Census ACS Data for FIPS 18109
From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 18109.
Median Household Income
$79,134
ACS B19013_001E
Poverty Rate
8.5%
ACS B17001 (below poverty level)
Median Age
41.5
ACS B01002_001E
Metropolitan Area
Adjacent Counties (7)
Counties that share a border with Morgan County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 18109.
Federal Datasets Using Code 18109
FIPS code 18109 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 18109 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:109",
"in": "state:18",
"key": "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json() # [[header...], [Morgan County, Indiana, income, pop, ...]-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '18109';
-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '18'
AND county_fips = '109';
-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 18109 is WRONG for this countylibrary(tidycensus)
get_acs(
geography = "county",
variables = c(income = "B19013_001E", pop = "B01003_001E"),
state = "18",
county = "109",
year = 2022
)ZIP Codes in Morgan 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 Morgan County. Why FIPS ≠ ZIP →
| ZIP Code | % in county |
|---|---|
| 46125 | 100.0% |
| 46111 | 100.0% |
| 46157 | 100.0% |
| 46151 | 96.4% |
| 46166 | 95.4% |
| 46158 | 88.6% |
| 46180 | 55.9% |
| 46113 | 47.7% |
| 46160 | 26.2% |
| 47456 | 19.7% |
| 47433 | 14.3% |
| 46118 | 7.4% |
| 46120 | 5.8% |
| 46106 | 3.5% |