53033 FipsDecoder
55009 County FIPS Code

Brown County

Wisconsin · County seat: Green Bay · Active county or equivalent

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FIPS code 55009 is Brown County, Wisconsin. With a population of 268,393 (2022 ACS estimate), it ranks #4 in Wisconsin and #260 nationally. Brown County is part of the Green Bay, WI. The state FIPS code for Wisconsin is 55. This code is used in Census Bureau, BLS, EPA, HUD, and USDA federal datasets to identify this county.

County FIPS

55009

State FIPS

55

WI

Population

268,393

2022 ACS · #260 nationally

Density

506.7/mi²

people per sq mile

Land Area

530

sq miles

Urban/Rural

Metro — 250K–1M population

RUCC 2

How This FIPS Code Works

55 009
55 = State FIPS (Wisconsin)
009 = County FIPS

The 5-digit FIPS code 55009 is formed by combining the 2-digit state identifier 55 (Wisconsin) with the 3-digit county identifier 009. Together they uniquely identify Brown County in every US federal dataset. No two counties share the same 5-digit FIPS code.

Census ACS Data for FIPS 55009

From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 55009.

Median Household Income

$74,066

ACS B19013_001E

Poverty Rate

9.7%

ACS B17001 (below poverty level)

Median Age

37.8

ACS B01002_001E

Metropolitan Area

Adjacent Counties (7)

Counties that share a border with Brown County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 55009.

Federal Datasets Using Code 55009

FIPS code 55009 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 55009 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.

Census ACS API — Python 55009
import requests

url = "https://api.census.gov/data/2022/acs/acs5"
params = {
    "get":  "NAME,B19013_001E,B01003_001E",
    "for":  "county:009",
    "in":   "state:55",
    "key":  "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json()  # [[header...], [Brown County, Wisconsin, income, pop, ...]
SQL — filtering by county FIPS 55009
-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '55009';

-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '55'
  AND county_fips = '009';

-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 55009 is WRONG for this county
R — tidycensus 55009
library(tidycensus)

get_acs(
  geography = "county",
  variables = c(income = "B19013_001E", pop = "B01003_001E"),
  state     = "55",
  county    = "009",
  year      = 2022
)
Zero-padding reminder: FIPS codes must always be stored and compared as zero-padded strings. 55 (not 55) and 009 (not 9) — losing the leading zeros is one of the most common data-join bugs in federal datasets. Full guide →

ZIP Codes in Brown 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 Brown County. Why FIPS ≠ ZIP →

ZIP Code % in county
54229 100.0%
54173 100.0%
54303 100.0%
54302 100.0%
54301 100.0%
54311 100.0%
54307 100.0%
54304 100.0%
54126 99.4%
54313 98.7%
54180 85.0%
54115 84.9%
54208 59.0%
54155 50.1%
54162 22.5%
54217 11.8%
54130 10.4%
54110 2.8%
54165 1.1%

Other Counties in Wisconsin