What city is 21029 in?

21029 is a Clarksville, MD mailing address. By land area, 16% lies inside Columbia; the rest is outside any Census-defined city or community.

What is the population of 21029?

About 13,607 people (±1,382), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 12,919.

What is the median household income in 21029?

$243,542 (±$22,415), 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 21029?

10 USPS carrier routes with 4,113 residential and 208 business mailboxes (4,321 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.

What ZIP codes are near 21029?

The closest, measured center to center: 20777 (2.7 mi, Highland), 21036 (2.9 mi), 20862 (3.8 mi, Ashton-Sandy Spring), 21737 (4.3 mi), 20759 (4.4 mi, Fulton) and 21044 (4.4 mi, Columbia).

21029 ZIP Code, Clarksville, MD

21029 is a ZIP code in Clarksville, Maryland in Howard County. It covers 17 square miles of land. The closest ZIP codes are 20777, 21036 and 20862. 13,607 people live here in 4,056 households. With about 804 people per square mile it is lightly settled, and most homes are owner-occupied (94%). Median household income is $243,542, well above the Maryland median of $103,678; 51% of households have children under 18.

Quick facts

Mailing city: Clarksville, MD
County: Howard County
Land area: 17 sq mi
Population: 13,607
Median household income: $243,542
Carrier routes: 10 (4,113 homes)

Key figures

Measure	Value
Residents	13,607
Households	4,056
Median household income	$243,542
Income per person	$89,689
Median age	43.1
Homeowners	93.6%
Median home value	$912,100
Median rent	$3,501
Bachelor's degree or higher	81.4%
Average commute (minutes)	32.4
Households with kids under 18	51.4%
Moved in the past year	8.8%
Below the poverty line	1.1%
Broadband internet	98.1%
Speak a non-English language at home	44.7%

Household income

% of households	Value
<$10K	0.9%
$10–15K	0.0%
$15–25K	2.2%
$25–35K	0.5%
$35–50K	1.1%
$50–75K	4.0%
$75–100K	4.3%
$100–150K	9.9%
$150–200K	12.4%
$200K+	64.7%

Age

% of all residents	Value
<10	10.0%
10–19	20.0%
20–24	5.4%
25–34	4.5%
35–44	12.4%
45–54	19.5%
55–64	15.4%
65–74	8.8%
75+	4.0%

Tenure

% of housing units	Value
Owned, with mortgage	64.5%
Owned outright	27.7%
Rented	6.2%
Vacant	1.6%

Type of building

% of housing units	Value
Detached house	89.7%
Townhome	6.7%
2–4 units	0.0%
5–19 units	0.6%
20+ units	2.6%
Mobile / other	0.4%

Businesses in 21029

401 business establishments with 3,928 employees (ZIP Codes Business Patterns 2023).

Professional, Scientific, and Technical Services: 109
Health Care and Social Assistance: 56
Retail Trade: 40
Accommodation and Food Services: 37
Other Services (except Public Administration): 34
Finance and Insurance: 28
Real Estate and Rental and Leasing: 23
Construction: 21

EDDM carrier routes

21029 has 10 USPS carrier routes with 4,113 residential and 208 business mailboxes. Open the EDDM route map.

Carrier routes in 21029

21029 has 10 USPS carrier routes (10 rural (R)) with 4,113 residential and 208 business mailboxes. Routes range from 134 homes (R290) to 531 homes (R296); the median route has 452 homes. The Census counted 4,056 households in 21029 (2020–2024 average); USPS counts current mailboxes, including new and vacant homes.

Homes per route	Routes
1–249	1
250–499	8
500–749	1
750–999	0
1,000–1,499	0
1,500+	0

Best routes in 21029 for…

Most businesses

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

Route R299 — USPS business mailboxes 120, 335 homes
Route R298 — USPS business mailboxes 35, 455 homes
Route R294 — USPS business mailboxes 18, 435 homes
Route R290 — USPS business mailboxes 15, 134 homes
Route R296 — USPS business mailboxes 14, 531 homes

Select these 5 routes on the route map

Every carrier route in 21029

Route	Type	Homes	Businesses	Est. median income	Est. owners	Est. families with kids	Est. moved in past year
R290	Rural	134	15	$200,001+	—	—	—
R291	Rural	381	5	$200,001+	—	—	—
R292	Rural	471	0	$200,001+	—	—	—
R293	Rural	449	0	$194,456	—	—	—
R294	Rural	435	18	$200,001+	—	—	—
R295	Rural	457	1	$200,001+	—	—	—
R296	Rural	531	14	$200,001+	—	—	—
R297	Rural	465	0	$200,001+	—	—	—
R298	Rural	455	35	$200,001+	—	—	—
R299	Rural	335	120	$200,001+	—	—	—

Income, owners, families and movers are estimates for each route (how we estimate them); mailbox counts are current USPS figures. Open 21029 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

20777 — Highland CDP, MD (2.7 mi)
21036 (2.9 mi)
20862 — Ashton-Sandy Spring CDP, MD (3.8 mi)
21737 (4.3 mi)
20759 — Fulton CDP, MD (4.4 mi)
21044 — Columbia CDP, MD (4.4 mi)
20861 — Ashton-Sandy Spring CDP, MD (5 mi)
20833 — Olney CDP, MD (5.5 mi)

Areas that include 21029

Where it ranks

Mail every home in 21029

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) 21029, which approximates the USPS ZIP code area. Census figures: American Community Survey 5-year estimates, 2020–2024.

Frequently asked questions

What city is 21029 in?: 21029 is a Clarksville, MD mailing address. By land area, 16% lies inside Columbia; the rest is outside any Census-defined city or community.
What county is 21029 in?: 21029 is in Howard County.
What is the population of 21029?: About 13,607 people (±1,382), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 12,919.
What is the median household income in 21029?: $243,542 (±$22,415), 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 21029?: 10 USPS carrier routes with 4,113 residential and 208 business mailboxes (4,321 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.
What ZIP codes are near 21029?: The closest, measured center to center: 20777 (2.7 mi, Highland), 21036 (2.9 mi), 20862 (3.8 mi, Ashton-Sandy Spring), 21737 (4.3 mi), 20759 (4.4 mi, Fulton) and 21044 (4.4 mi, Columbia).

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