53033 FipsDecoder
25021 County FIPS Code

Norfolk County

Massachusetts · County seat: Dedham · Active county or equivalent

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FIPS code 25021 is Norfolk County, Massachusetts. With a population of 722,112 (2022 ACS estimate), it ranks #5 in Massachusetts and #89 nationally. Norfolk County is part of the Boston-Cambridge-Newton, MA-NH. The state FIPS code for Massachusetts is 25. This code is used in Census Bureau, BLS, EPA, HUD, and USDA federal datasets to identify this county.

County FIPS

25021

State FIPS

25

MA

Population

722,112

2022 ACS · #89 nationally

Density

1,823.0/mi²

people per sq mile

Land Area

396

sq miles

Urban/Rural

Metro — 1M+ population

RUCC 1

How This FIPS Code Works

25 021
25 = State FIPS (Massachusetts)
021 = County FIPS

The 5-digit FIPS code 25021 is formed by combining the 2-digit state identifier 25 (Massachusetts) with the 3-digit county identifier 021. Together they uniquely identify Norfolk County in every US federal dataset. No two counties share the same 5-digit FIPS code.

Census ACS Data for FIPS 25021

From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 25021.

Median Household Income

$120,621

ACS B19013_001E

Poverty Rate

6.5%

ACS B17001 (below poverty level)

Median Age

40.7

ACS B01002_001E

Metropolitan Area

Adjacent Counties (6)

Counties that share a border with Norfolk County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 25021.

Federal Datasets Using Code 25021

FIPS code 25021 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 25021 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 25021
import requests

url = "https://api.census.gov/data/2022/acs/acs5"
params = {
    "get":  "NAME,B19013_001E,B01003_001E",
    "for":  "county:021",
    "in":   "state:25",
    "key":  "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json()  # [[header...], [Norfolk County, Massachusetts, income, pop, ...]
SQL — filtering by county FIPS 25021
-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '25021';

-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '25'
  AND county_fips = '021';

-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 25021 is WRONG for this county
R — tidycensus 25021
library(tidycensus)

get_acs(
  geography = "county",
  variables = c(income = "B19013_001E", pop = "B01003_001E"),
  state     = "25",
  county    = "021",
  year      = 2022
)
Zero-padding reminder: FIPS codes must always be stored and compared as zero-padded strings. 25 (not 25) and 021 (not 21) — losing the leading zeros is one of the most common data-join bugs in federal datasets. Full guide →

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

ZIP Code % in county
02343 100.0%
02021 100.0%
02025 100.0%
02026 100.0%
02030 100.0%
02032 100.0%
02035 100.0%
02038 100.0%
02052 100.0%
02053 100.0%
02054 100.0%
02056 100.0%
02062 100.0%
02067 100.0%
02071 100.0%
02072 100.0%
02081 100.0%
02090 100.0%
02093 100.0%
02169 100.0%
02170 100.0%
02171 100.0%
02184 100.0%
02186 100.0%
02188 100.0%
02189 100.0%
02190 100.0%
02191 100.0%
02482 100.0%
02492 100.0%

Showing top 30 of 41 ZIP codes by residential address share.

Other Counties in Massachusetts