FIPS code 31055 is Douglas County, Nebraska. With a population of 582,638 (2022 ACS estimate), it ranks #1 in Nebraska and #114 nationally. Douglas County is part of the Omaha, NE-IA. The state FIPS code for Nebraska is 31. This code is used in Census Bureau, BLS, EPA, HUD, and USDA federal datasets to identify this county.
County FIPS
31055
Population
582,638
2022 ACS · #114 nationally
Density
1,773.9/mi²
people per sq mile
Land Area
328
sq miles
Urban/Rural
Metro — 250K–1M population
RUCC 2
How This FIPS Code Works
The 5-digit FIPS code 31055 is formed by combining the 2-digit state identifier 31 (Nebraska) with the 3-digit county identifier 055. Together they uniquely identify Douglas County in every US federal dataset. No two counties share the same 5-digit FIPS code.
Census ACS Data for FIPS 31055
From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 31055.
Median Household Income
$76,083
ACS B19013_001E
Poverty Rate
11.0%
ACS B17001 (below poverty level)
Median Age
35.3
ACS B01002_001E
Metropolitan Area
Adjacent Counties (5)
Counties that share a border with Douglas County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 31055.
Federal Datasets Using Code 31055
FIPS code 31055 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 31055 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:055",
"in": "state:31",
"key": "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json() # [[header...], [Douglas County, Nebraska, income, pop, ...]-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '31055';
-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '31'
AND county_fips = '055';
-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 31055 is WRONG for this countylibrary(tidycensus)
get_acs(
geography = "county",
variables = c(income = "B19013_001E", pop = "B01003_001E"),
state = "31",
county = "055",
year = 2022
)ZIP Codes in Douglas 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 Douglas County. Why FIPS ≠ ZIP →
| ZIP Code | % in county |
|---|---|
| 68154 | 100.0% |
| 68010 | 100.0% |
| 68022 | 100.0% |
| 68178 | 100.0% |
| 68144 | 100.0% |
| 68164 | 100.0% |
| 68102 | 100.0% |
| 68104 | 100.0% |
| 68105 | 100.0% |
| 68106 | 100.0% |
| 68107 | 100.0% |
| 68108 | 100.0% |
| 68110 | 100.0% |
| 68111 | 100.0% |
| 68183 | 100.0% |
| 68114 | 100.0% |
| 68116 | 100.0% |
| 68117 | 100.0% |
| 68118 | 100.0% |
| 68182 | 100.0% |
| 68124 | 100.0% |
| 68127 | 100.0% |
| 68130 | 100.0% |
| 68131 | 100.0% |
| 68132 | 100.0% |
| 68134 | 100.0% |
| 68135 | 100.0% |
| 68137 | 100.0% |
| 68064 | 90.9% |
| 68069 | 89.3% |
Showing top 30 of 37 ZIP codes by residential address share.