What city is 21001 in?

21001 is a Aberdeen, MD mailing address. By land area, 21% lies inside Aberdeen and 16% lies inside Perryman; the rest is outside any Census-defined city or community.

What is the population of 21001?

About 27,168 people (±986), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 25,714.

What is the median household income in 21001?

$83,238 (±$8,360), compared with $103,678 for Maryland as a whole. Half the households in the ZIP code earn more and half earn less.

How many carrier routes and mailboxes are in 21001?

17 USPS carrier routes with 12,341 residential and 596 business mailboxes (12,941 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.

What ZIP codes are near 21001?

The closest, measured center to center: 21130 (2.1 mi, Perryman), 21017 (2.7 mi, Riverside), 21078 (4.9 mi, Havre de Grace), 21009 (5 mi, Bel Air South), 21028 (5 mi) and 21005 (5.3 mi, Aberdeen Proving Ground).

21001 ZIP Code, Aberdeen, MD

21001 is a ZIP code in Aberdeen, Maryland in Harford County. It covers 30 square miles of land. The closest ZIP codes are 21130, 21017 and 21078. 27,168 people live here in 11,204 households. With about 907 people per square mile it is lightly settled, and owners and renters are mixed (63% own). Median household income is $83,238, below the Maryland median of $103,678.

Quick facts

Mailing city: Aberdeen, MD
County: Harford County
Land area: 30 sq mi
Population: 27,168
Median household income: $83,238
Carrier routes: 17 (12,341 homes)

Key figures

Measure	Value
Residents	27,168
Households	11,204
Median household income	$83,238
Income per person	$41,898
Median age	37.7
Homeowners	63.3%
Median home value	$285,800
Median rent	$1,442
Bachelor's degree or higher	28.2%
Average commute (minutes)	29.1
Households with kids under 18	30.7%
Moved in the past year	10.2%
Below the poverty line	12.7%
Broadband internet	90.9%
Speak a non-English language at home	11.2%

Household income

% of households	Value
<$10K	7.1%
$10–15K	3.0%
$15–25K	4.2%
$25–35K	5.1%
$35–50K	11.2%
$50–75K	15.5%
$75–100K	12.8%
$100–150K	20.5%
$150–200K	9.8%
$200K+	10.9%

Age

% of all residents	Value
<10	10.3%
10–19	14.3%
20–24	5.4%
25–34	16.4%
35–44	13.8%
45–54	10.5%
55–64	14.1%
65–74	10.2%
75+	5.1%

Tenure

% of housing units	Value
Owned, with mortgage	44.2%
Owned outright	17.4%
Rented	34.9%
Vacant	3.4%

Type of building

% of housing units	Value
Detached house	52.4%
Townhome	17.7%
2–4 units	2.1%
5–19 units	16.6%
20+ units	6.1%
Mobile / other	5.2%

Businesses in 21001

551 business establishments with 11,492 employees (ZIP Codes Business Patterns 2023).

Retail Trade: 84
Health Care and Social Assistance: 71
Accommodation and Food Services: 71
Other Services (except Public Administration): 59
Professional, Scientific, and Technical Services: 52
Construction: 43
Transportation and Warehousing: 38
Administrative and Support and Waste Management and Remediation Services: 25

EDDM carrier routes

21001 has 17 USPS carrier routes with 12,341 residential and 596 business mailboxes. Open the EDDM route map.

Carrier routes in 21001

21001 has 17 USPS carrier routes (8 city (C), 9 rural (R)) with 12,341 residential and 596 business mailboxes. Routes range from 67 homes (C004) to 1,115 homes (R007); the median route has 761 homes. The Census counted 11,204 households in 21001 (2020–2024 average); USPS counts current mailboxes, including new and vacant homes.

Homes per route	Routes
1–249	1
250–499	3
500–749	4
750–999	6
1,000–1,499	3
1,500+	0

Best routes in 21001 for…

Most businesses

For B2B offers: office supplies, cleaning, IT, catering and commercial services.

Route R008 — USPS business mailboxes 210, 468 homes
Route C004 — USPS business mailboxes 113, 67 homes
Route C008 — USPS business mailboxes 45, 805 homes
Route R010 — USPS business mailboxes 41, 1,017 homes
Route R002 — USPS business mailboxes 41, 738 homes

Select these 5 routes on the route map

Every carrier route in 21001

Route	Type	Homes	Businesses	Est. median income	Est. owners	Est. families with kids	Est. moved in past year
C001	City	629	6	$107,692	—	—	—
C002	City	761	38	$50,000	—	—	—
C004	City	67	113	$50,000	—	—	—
C005	City	939	16	$147,579	—	—	—
C006	City	448	3	$108,204	—	—	—
C008	City	805	45	$108,204	—	—	—
C009	City	496	20	$46,941	—	—	—
C010	City	696	6	$87,249	—	—	—
R001	Rural	794	8	$86,187	—	—	—
R002	Rural	738	41	$112,515	—	—	—
R003	Rural	769	14	$76,670	—	—	—
R005	Rural	711	7	$70,237	—	—	—
R006	Rural	1,030	0	$104,805	—	—	—
R007	Rural	1,115	6	$94,590	—	—	—
R008	Rural	468	210	$76,670	—	—	—
R009	Rural	858	22	$27,061	—	—	—
R010	Rural	1,017	41	$40,377	—	—	—

Income, owners, families and movers are estimates for each route (how we estimate them); mailbox counts are current USPS figures. Open 21001 on the EDDM route map.

How route demographics are estimated

Mailbox counts come from USPS; demographics are estimates

The number of homes and businesses on each carrier route is the current USPS EDDM count. The Census Bureau does not publish figures for carrier routes, so income, homeownership, ages, families, movers and housing age on a route are EDDM2GO estimates built from Census block groups (neighborhood areas of roughly 600 to 3,000 people).

How a route gets its figures: the block-group length-share method

We trace each route's streets every 25 meters and record which block group each stretch falls in. The route's homes are spread along its streets in proportion to length, so a route with 60% of its street length in one block group is assumed to have 60% of its homes there. Each block group then contributes its Census counts in proportion to the share of its housing units that sit on the route (capped at the whole block group). Medians are recalculated from the combined income, home-value and age brackets, the way the Census Bureau computes them, not averaged.

Margins of error

Census survey figures carry a margin of error at 90% confidence; we carry it through the calculation and show it as ±. Our margins treat the route-to-block-group split as exact, so the real uncertainty is larger. Routes with fewer than 100 estimated households, large margins, or streets we could not place are flagged.

Different years

USPS mailbox counts are current. Census figures are 5-year averages for 2020–2024, so a new subdivision may have more homes on the route today than the Census counted. Use the route figures to compare routes with each other, not as an exact head count.

Why some routes show identical figures

Two routes that run through the same block group get the same percentages and medians, because the Census publishes one set of figures for the whole block group. Their mailbox counts still differ, and those are exact.

Route and mailbox counts: USPS EDDM route data. Route demographics: EDDM2GO estimates from U.S. Census Bureau American Community Survey 5-year block-group data (2020–2024) and 2024 cartographic block-group boundaries. This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.

Nearby ZIP codes

21130 — Perryman CDP, MD (2.1 mi)
21017 — Riverside CDP, MD (2.7 mi)
21078 — Havre de Grace city, MD (4.9 mi)
21009 — Bel Air South CDP, MD (5 mi)
21028 (5 mi)
21005 — Aberdeen Proving Ground CDP, MD (5.3 mi)
21015 — Bel Air South CDP, MD (5.6 mi)
21040 — Edgewood CDP, MD (6.8 mi)

Areas that include 21001

Where it ranks

Mail every home in 21001

Route counts on this page price as Full Service 6.5 × 9 postcards: we print, bundle by carrier route and hand the mailing to USPS. Prefer to take it to the Post Office yourself? Print only costs less and you pay postage at drop-off.

EDDM guides

ZIP code statistics describe the Census ZIP Code Tabulation Area (ZCTA) 21001, which approximates the USPS ZIP code area. Census figures: American Community Survey 5-year estimates, 2020–2024.

Frequently asked questions

What city is 21001 in?: 21001 is a Aberdeen, MD mailing address. By land area, 21% lies inside Aberdeen and 16% lies inside Perryman; the rest is outside any Census-defined city or community.
What county is 21001 in?: 21001 is in Harford County.
What is the population of 21001?: About 27,168 people (±986), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 25,714.
What is the median household income in 21001?: $83,238 (±$8,360), compared with $103,678 for Maryland as a whole. Half the households in the ZIP code earn more and half earn less.
How many carrier routes and mailboxes are in 21001?: 17 USPS carrier routes with 12,341 residential and 596 business mailboxes (12,941 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.
What ZIP codes are near 21001?: The closest, measured center to center: 21130 (2.1 mi, Perryman), 21017 (2.7 mi, Riverside), 21078 (4.9 mi, Havre de Grace), 21009 (5 mi, Bel Air South), 21028 (5 mi) and 21005 (5.3 mi, Aberdeen Proving Ground).

This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.