FIPS code 19123 is Mahaska County, Iowa. With a population of 22,059 (2022 ACS estimate), it ranks #28 in Iowa and #1762 nationally. Mahaska County is part of the Oskaloosa, IA. The state FIPS code for Iowa is 19. This code is used in Census Bureau, BLS, EPA, HUD, and USDA federal datasets to identify this county.
County FIPS
19123
Population
22,059
2022 ACS · #1762 nationally
Density
38.6/mi²
people per sq mile
Land Area
571
sq miles
Urban/Rural
Nonmetro — urban 2.5K–19.9K, not adjacent to metro
RUCC 7
How This FIPS Code Works
The 5-digit FIPS code 19123 is formed by combining the 2-digit state identifier 19 (Iowa) with the 3-digit county identifier 123. Together they uniquely identify Mahaska County in every US federal dataset. No two counties share the same 5-digit FIPS code.
Census ACS Data for FIPS 19123
From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 19123.
Median Household Income
$65,200
ACS B19013_001E
Poverty Rate
12.0%
ACS B17001 (below poverty level)
Median Age
39.6
ACS B01002_001E
Metropolitan Area
Adjacent Counties (6)
Counties that share a border with Mahaska County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 19123.
Federal Datasets Using Code 19123
FIPS code 19123 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 19123 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:123",
"in": "state:19",
"key": "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json() # [[header...], [Mahaska County, Iowa, income, pop, ...]-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '19123';
-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '19'
AND county_fips = '123';
-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 19123 is WRONG for this countylibrary(tidycensus)
get_acs(
geography = "county",
variables = c(income = "B19013_001E", pop = "B01003_001E"),
state = "19",
county = "123",
year = 2022
)ZIP Codes in Mahaska 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 Mahaska County. Why FIPS ≠ ZIP →
| ZIP Code | % in county |
|---|---|
| 52534 | 100.0% |
| 52595 | 100.0% |
| 52577 | 100.0% |
| 52543 | 100.0% |
| 50027 | 99.3% |
| 50143 | 98.7% |
| 50207 | 97.6% |
| 52586 | 96.9% |
| 52561 | 83.7% |
| 50044 | 36.5% |
| 50219 | 36.2% |
| 52553 | 34.1% |
| 50256 | 23.5% |
| 50268 | 18.4% |
| 50104 | 9.6% |
| 50153 | 8.8% |
| 50251 | 3.2% |
| 52550 | 2.4% |
| 50171 | 1.6% |
| 52501 | 0.2% |