What city is 21756 in?

21756 is a Keedysville, MD mailing address. By land area, 4% lies inside Keedysville, 3% lies inside Mount Briar and 2% lies inside Trego-Rohrersville Station; the rest is outside any Census-defined city or community.

What is the population of 21756?

About 3,640 people (±563), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 3,669.

What is the median household income in 21756?

$101,786 (±$29,588), 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 21756?

3 USPS carrier routes with 1,319 residential and 9 business mailboxes (1,328 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.

What ZIP codes are near 21756?

The closest, measured center to center: 21779 (3.2 mi, Gapland), 21782 (3.6 mi, Mercersville), 21713 (4.7 mi, Boonsboro), 21718 (5.8 mi, Burkittsville), 21715 (5.9 mi, Brownsville) and 25443 (6.6 mi, Shepherdstown).

21756 ZIP Code, Keedysville, MD

21756 is a ZIP code in Keedysville, Maryland in Washington County. It covers 23 square miles of land. The closest ZIP codes are 21779, 21782 and 21713. 3,640 people live here in 1,394 households. With about 156 people per square mile it is lightly settled, and most homes are owner-occupied (98%). Median household income is $101,786, close to the Maryland median of $103,678; 42% of households have children under 18.

Quick facts

Mailing city: Keedysville, MD
County: Washington County
Land area: 23 sq mi
Population: 3,640
Median household income: $101,786
Carrier routes: 3 (1,319 homes)

Key figures

Measure	Value
Residents	3,640
Households	1,394
Median household income	$101,786
Income per person	$48,757
Median age	41.8
Homeowners	97.7%
Median home value	$413,200
Median rent	$1,321
Bachelor's degree or higher	28.8%
Average commute (minutes)	44.4
Households with kids under 18	41.5%
Moved in the past year	8.6%
Below the poverty line	2.9%
Broadband internet	96.8%
Speak a non-English language at home	1.9%

Household income

% of households	Value
<$10K	3.1%
$10–15K	0.9%
$15–25K	2.0%
$25–35K	14.5%
$35–50K	1.9%
$50–75K	15.1%
$75–100K	11.4%
$100–150K	16.2%
$150–200K	17.1%
$200K+	17.7%

Age

% of all residents	Value
<10	12.8%
10–19	14.1%
20–24	5.7%
25–34	8.9%
35–44	11.3%
45–54	15.5%
55–64	15.7%
65–74	9.1%
75+	6.9%

Tenure

% of housing units	Value
Owned, with mortgage	51.7%
Owned outright	39.8%
Rented	2.0%
Vacant	6.5%

Type of building

% of housing units	Value
Detached house	98.0%
Townhome	0.2%
2–4 units	0.4%
5–19 units	0.0%
20+ units	0.0%
Mobile / other	1.4%

Businesses in 21756

48 business establishments with 161 employees (ZIP Codes Business Patterns 2023).

Construction: 14
Transportation and Warehousing: 6
Manufacturing: 4
Professional, Scientific, and Technical Services: 4
Other Services (except Public Administration): 4
Administrative and Support and Waste Management and Remediation Services: 3
Health Care and Social Assistance: 3

EDDM carrier routes

21756 has 3 USPS carrier routes with 1,319 residential and 9 business mailboxes. Open the EDDM route map.

Carrier routes in 21756

21756 has 3 USPS carrier routes (3 rural (R)) with 1,319 residential and 9 business mailboxes. Routes range from 99 homes (R003) to 642 homes (R001); the median route has 578 homes. The Census counted 1,394 households in 21756 (2020–2024 average); USPS counts current mailboxes, including new and vacant homes.

Homes per route	Routes
1–249	1
250–499	0
500–749	2
750–999	0
1,000–1,499	0
1,500+	0

Best routes in 21756 for…

Most businesses

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

Route R002 — USPS business mailboxes 4, 578 homes
Route R003 — USPS business mailboxes 4, 99 homes
Route R001 — USPS business mailboxes 1, 642 homes

Select these 3 routes on the route map

Every carrier route in 21756

Route	Type	Homes	Businesses	Est. median income	Est. owners	Est. families with kids	Est. moved in past year
R001	Rural	642	1	$53,635	—	—	—
R002	Rural	578	4	$114,800	—	—	—
R003	Rural	99	4	$122,140	—	—	—

Income, owners, families and movers are estimates for each route (how we estimate them); mailbox counts are current USPS figures. Open 21756 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

21779 — Gapland CDP, MD (3.2 mi)
21782 — Mercersville CDP, MD (3.6 mi)
21713 — Boonsboro town, MD (4.7 mi)
21718 — Burkittsville town, MD (5.8 mi)
21715 — Brownsville CDP, MD (5.9 mi)
25443 — Shepherdstown town, WV (6.6 mi)
21769 — Middletown town, MD (6.8 mi)
21733 — St. James CDP, MD (7.1 mi)

Areas that include 21756

Keedysville, MD ZIP codes — 1 ZIP code
Trego-Rohrersville Station, MD ZIP codes — 1 ZIP code
Mount Briar, MD ZIP codes — 1 ZIP code
Rohrersville, MD ZIP codes — 2 ZIP codes
Eakles Mill, MD ZIP codes — 1 ZIP code
Washington County ZIP codes — 19 ZIP codes
Maryland ZIP code data

Where it ranks

Mail every home in 21756

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) 21756, which approximates the USPS ZIP code area. Census figures: American Community Survey 5-year estimates, 2020–2024.

Frequently asked questions

What city is 21756 in?: 21756 is a Keedysville, MD mailing address. By land area, 4% lies inside Keedysville, 3% lies inside Mount Briar and 2% lies inside Trego-Rohrersville Station; the rest is outside any Census-defined city or community.
What county is 21756 in?: 21756 is in Washington County.
What is the population of 21756?: About 3,640 people (±563), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 3,669.
What is the median household income in 21756?: $101,786 (±$29,588), 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 21756?: 3 USPS carrier routes with 1,319 residential and 9 business mailboxes (1,328 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.
What ZIP codes are near 21756?: The closest, measured center to center: 21779 (3.2 mi, Gapland), 21782 (3.6 mi, Mercersville), 21713 (4.7 mi, Boonsboro), 21718 (5.8 mi, Burkittsville), 21715 (5.9 mi, Brownsville) and 25443 (6.6 mi, Shepherdstown).

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