53033 FipsDecoder
55089 County FIPS Code

Ozaukee County

Wisconsin · County seat: Port Washington · Active county or equivalent

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FIPS code 55089 is Ozaukee County, Wisconsin. With a population of 91,745 (2022 ACS estimate), it ranks #18 in Wisconsin and #648 nationally. Ozaukee County is part of the Milwaukee-Waukesha, 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

55089

State FIPS

55

WI

Population

91,745

2022 ACS · #648 nationally

Density

393.6/mi²

people per sq mile

Land Area

233

sq miles

Urban/Rural

Metro — 1M+ population

RUCC 1

How This FIPS Code Works

55 089
55 = State FIPS (Wisconsin)
089 = County FIPS

The 5-digit FIPS code 55089 is formed by combining the 2-digit state identifier 55 (Wisconsin) with the 3-digit county identifier 089. Together they uniquely identify Ozaukee County in every US federal dataset. No two counties share the same 5-digit FIPS code.

Census ACS Data for FIPS 55089

From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 55089.

Median Household Income

$92,258

ACS B19013_001E

Poverty Rate

4.5%

ACS B17001 (below poverty level)

Median Age

43.8

ACS B01002_001E

Metropolitan Area

Adjacent Counties (6)

Counties that share a border with Ozaukee County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 55089.

Federal Datasets Using Code 55089

FIPS code 55089 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 55089 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 55089
import requests

url = "https://api.census.gov/data/2022/acs/acs5"
params = {
    "get":  "NAME,B19013_001E,B01003_001E",
    "for":  "county:089",
    "in":   "state:55",
    "key":  "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json()  # [[header...], [Ozaukee County, Wisconsin, income, pop, ...]
SQL — filtering by county FIPS 55089
-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '55089';

-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '55'
  AND county_fips = '089';

-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 55089 is WRONG for this county
R — tidycensus 55089
library(tidycensus)

get_acs(
  geography = "county",
  variables = c(income = "B19013_001E", pop = "B01003_001E"),
  state     = "55",
  county    = "089",
  year      = 2022
)
Zero-padding reminder: FIPS codes must always be stored and compared as zero-padded strings. 55 (not 55) and 089 (not 89) — losing the leading zeros is one of the most common data-join bugs in federal datasets. Full guide →

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

ZIP Code % in county
53097 100.0%
53004 100.0%
53080 100.0%
53092 100.0%
53024 100.0%
53074 100.0%
53021 81.0%
53012 68.5%
53013 18.8%
53075 10.0%
53095 6.1%
53090 3.1%
53217 0.6%

Other Counties in Wisconsin