53033 FipsDecoder
24009 County FIPS Code

Calvert County

Maryland · County seat: Prince Frederick · Active county or equivalent

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FIPS code 24009 is Calvert County, Maryland. With a population of 93,244 (2022 ACS estimate), it ranks #15 in Maryland and #642 nationally. Calvert County is part of the Lexington Park, MD. The state FIPS code for Maryland is 24. This code is used in Census Bureau, BLS, EPA, HUD, and USDA federal datasets to identify this county.

County FIPS

24009

State FIPS

24

MD

Population

93,244

2022 ACS · #642 nationally

Density

437.5/mi²

people per sq mile

Land Area

213

sq miles

Urban/Rural

Metro — under 250K population

RUCC 3

How This FIPS Code Works

24 009
24 = State FIPS (Maryland)
009 = County FIPS

The 5-digit FIPS code 24009 is formed by combining the 2-digit state identifier 24 (Maryland) with the 3-digit county identifier 009. Together they uniquely identify Calvert County in every US federal dataset. No two counties share the same 5-digit FIPS code.

Census ACS Data for FIPS 24009

From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 24009.

Median Household Income

$128,078

ACS B19013_001E

Poverty Rate

4.3%

ACS B17001 (below poverty level)

Median Age

40.4

ACS B01002_001E

Metropolitan Area

Adjacent Counties (6)

Counties that share a border with Calvert County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 24009.

Federal Datasets Using Code 24009

FIPS code 24009 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 24009 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 24009
import requests

url = "https://api.census.gov/data/2022/acs/acs5"
params = {
    "get":  "NAME,B19013_001E,B01003_001E",
    "for":  "county:009",
    "in":   "state:24",
    "key":  "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json()  # [[header...], [Calvert County, Maryland, income, pop, ...]
SQL — filtering by county FIPS 24009
-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '24009';

-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '24'
  AND county_fips = '009';

-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 24009 is WRONG for this county
R — tidycensus 24009
library(tidycensus)

get_acs(
  geography = "county",
  variables = c(income = "B19013_001E", pop = "B01003_001E"),
  state     = "24",
  county    = "009",
  year      = 2022
)
Zero-padding reminder: FIPS codes must always be stored and compared as zero-padded strings. 24 (not 24) 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 Calvert 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 Calvert County. Why FIPS ≠ ZIP →

ZIP Code % in county
20615 100.0%
20629 100.0%
20639 100.0%
20657 100.0%
20676 100.0%
20678 100.0%
20685 100.0%
20688 100.0%
20689 100.0%
20732 100.0%
20736 97.0%
20754 83.1%
20714 35.8%
20758 2.5%

Other Counties in Maryland