53033 FipsDecoder
25023 County FIPS Code

Plymouth County

Massachusetts · County seat: Plymouth · Active county or equivalent

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FIPS code 25023 is Plymouth County, Massachusetts. With a population of 529,548 (2022 ACS estimate), it ranks #7 in Massachusetts and #131 nationally. Plymouth 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

25023

State FIPS

25

MA

Population

529,548

2022 ACS · #131 nationally

Density

803.5/mi²

people per sq mile

Land Area

659

sq miles

Urban/Rural

Metro — 1M+ population

RUCC 1

How This FIPS Code Works

25 023
25 = State FIPS (Massachusetts)
023 = County FIPS

The 5-digit FIPS code 25023 is formed by combining the 2-digit state identifier 25 (Massachusetts) with the 3-digit county identifier 023. Together they uniquely identify Plymouth County in every US federal dataset. No two counties share the same 5-digit FIPS code.

Census ACS Data for FIPS 25023

From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 25023.

Median Household Income

$105,387

ACS B19013_001E

Poverty Rate

6.7%

ACS B17001 (below poverty level)

Median Age

42.7

ACS B01002_001E

Metropolitan Area

Adjacent Counties (4)

Counties that share a border with Plymouth County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 25023.

Federal Datasets Using Code 25023

FIPS code 25023 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 25023 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 25023
import requests

url = "https://api.census.gov/data/2022/acs/acs5"
params = {
    "get":  "NAME,B19013_001E,B01003_001E",
    "for":  "county:023",
    "in":   "state:25",
    "key":  "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json()  # [[header...], [Plymouth County, Massachusetts, income, pop, ...]
SQL — filtering by county FIPS 25023
-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '25023';

-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '25'
  AND county_fips = '023';

-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 25023 is WRONG for this county
R — tidycensus 25023
library(tidycensus)

get_acs(
  geography = "county",
  variables = c(income = "B19013_001E", pop = "B01003_001E"),
  state     = "25",
  county    = "023",
  year      = 2022
)
Zero-padding reminder: FIPS codes must always be stored and compared as zero-padded strings. 25 (not 25) and 023 (not 23) — losing the leading zeros is one of the most common data-join bugs in federal datasets. Full guide →

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

ZIP Code % in county
02770 100.0%
02045 100.0%
02047 100.0%
02050 100.0%
02061 100.0%
02066 100.0%
02301 100.0%
02302 100.0%
02324 100.0%
02325 100.0%
02330 100.0%
02332 100.0%
02333 100.0%
02338 100.0%
02339 100.0%
02341 100.0%
02346 100.0%
02347 100.0%
02350 100.0%
02351 100.0%
02359 100.0%
02360 100.0%
02364 100.0%
02366 100.0%
02367 100.0%
02370 100.0%
02379 100.0%
02382 100.0%
02043 100.0%
02538 100.0%

Showing top 30 of 36 ZIP codes by residential address share.

Other Counties in Massachusetts