FIPS code 39109 is Miami County, Ohio. With a population of 108,818 (2022 ACS estimate), it ranks #25 in Ohio and #563 nationally. Miami County is part of the Dayton-Kettering-Beavercreek, OH. The state FIPS code for Ohio is 39. This code is used in Census Bureau, BLS, EPA, HUD, and USDA federal datasets to identify this county.
County FIPS
39109
Population
108,818
2022 ACS · #563 nationally
Density
267.6/mi²
people per sq mile
Land Area
407
sq miles
Urban/Rural
Metro — 250K–1M population
RUCC 2
How This FIPS Code Works
The 5-digit FIPS code 39109 is formed by combining the 2-digit state identifier 39 (Ohio) with the 3-digit county identifier 109. Together they uniquely identify Miami County in every US federal dataset. No two counties share the same 5-digit FIPS code.
Census ACS Data for FIPS 39109
From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 39109.
Median Household Income
$71,440
ACS B19013_001E
Poverty Rate
8.5%
ACS B17001 (below poverty level)
Median Age
41.1
ACS B01002_001E
Metropolitan Area
Adjacent Counties (5)
Counties that share a border with Miami County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 39109.
Federal Datasets Using Code 39109
FIPS code 39109 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 39109 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:39",
"key": "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json() # [[header...], [Miami County, Ohio, income, pop, ...]-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '39109';
-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '39'
AND county_fips = '109';
-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 39109 is WRONG for this countylibrary(tidycensus)
get_acs(
geography = "county",
variables = c(income = "B19013_001E", pop = "B01003_001E"),
state = "39",
county = "109",
year = 2022
)ZIP Codes in Miami 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 Miami County. Why FIPS ≠ ZIP →
| ZIP Code | % in county |
|---|---|
| 45373 | 100.0% |
| 45383 | 100.0% |
| 45326 | 100.0% |
| 45339 | 100.0% |
| 45359 | 100.0% |
| 45361 | 100.0% |
| 45318 | 99.3% |
| 45312 | 98.0% |
| 45371 | 95.7% |
| 45356 | 84.5% |
| 45337 | 62.9% |
| 45317 | 38.1% |
| 45308 | 27.4% |
| 45322 | 22.5% |
| 45344 | 20.3% |
| 45424 | 4.2% |
| 45309 | 2.3% |
| 45304 | 0.6% |