21131 ZIP Code, Phoenix, MD

21131 is a ZIP code in Phoenix, Maryland in Baltimore County. It covers 21 square miles of land. The closest ZIP codes are 21031, 21111 and 21013. 7,141 people live here in 2,600 households. With about 340 people per square mile it is lightly settled, and most homes are owner-occupied (98%). Median household income is $197,619, well above the Maryland median of $103,678; the median age is 49.4, older than most ZIP codes.

Quick facts

Key figures

MeasureValue
Residents7,141
Households2,600
Median household income$197,619
Income per person$82,991
Median age49.4
Homeowners98.4%
Median home value$686,000
Median rentnot published
Bachelor's degree or higher73.9%
Average commute (minutes)30
Households with kids under 1834.2%
Moved in the past year3.9%
Below the poverty line4.7%
Broadband internet96.8%
Speak a non-English language at home5.3%

Household income

% of householdsValue
<$10K3.8%
$10–15K2.3%
$15–25K1.2%
$25–35K1.3%
$35–50K4.0%
$50–75K4.2%
$75–100K7.3%
$100–150K14.7%
$150–200K12.0%
$200K+49.2%

Age

% of all residentsValue
<1010.2%
10–1913.7%
20–242.5%
25–346.7%
35–4412.6%
45–5414.0%
55–6418.1%
65–7413.8%
75+8.4%

Tenure

% of housing unitsValue
Owned, with mortgage60.2%
Owned outright36.1%
Rented1.5%
Vacant2.2%

Type of building

% of housing unitsValue
Detached house98.2%
Townhome1.3%
2–4 units0.0%
5–19 units0.0%
20+ units0.0%
Mobile / other0.5%

Businesses in 21131

215 business establishments with 1,746 employees (ZIP Codes Business Patterns 2023).

EDDM carrier routes

21131 has 6 USPS carrier routes with 2,761 residential and 111 business mailboxes. Open the EDDM route map.

Carrier routes in 21131

21131 has 6 USPS carrier routes (6 rural (R)) with 2,761 residential and 111 business mailboxes. Routes range from 420 homes (R005) to 493 homes (R003); the median route has 461 homes. The Census counted 2,600 households in 21131 (2020–2024 average); USPS counts current mailboxes, including new and vacant homes.

Homes per routeRoutes
1–2490
250–4996
500–7490
750–9990
1,000–1,4990
1,500+0

Best routes in 21131 for…

Most businesses

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

  1. Route R002 — USPS business mailboxes 37, 463 homes
  2. Route R005 — USPS business mailboxes 29, 420 homes
  3. Route R004 — USPS business mailboxes 28, 458 homes
  4. Route R003 — USPS business mailboxes 9, 493 homes
  5. Route R006 — USPS business mailboxes 4, 486 homes

Select these 5 routes on the route map

Every carrier route in 21131

RouteTypeHomesBusinessesEst. median incomeEst. ownersEst. families with kidsEst. moved in past year
R001Rural4414$200,001+———
R002Rural46337$184,296———
R003Rural4939$179,607———
R004Rural45828$200,001+———
R005Rural42029$179,607———
R006Rural4864$200,001+———

Income, owners, families and movers are estimates for each route (how we estimate them); mailbox counts are current USPS figures. Open 21131 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

Areas that include 21131

Where it ranks

Mail every home in 21131

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) 21131, which approximates the USPS ZIP code area. Census figures: American Community Survey 5-year estimates, 2020–2024.

Frequently asked questions

What city is 21131 in?
21131 is a Phoenix, MD mailing address. By land area, 3% lies inside Cockeysville; the rest is outside any Census-defined city or community.
What county is 21131 in?
21131 is in Baltimore County.
What is the population of 21131?
About 7,141 people (±872), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 7,468.
What is the median household income in 21131?
$197,619 (±$35,903), 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 21131?
6 USPS carrier routes with 2,761 residential and 111 business mailboxes (2,872 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.
What ZIP codes are near 21131?
The closest, measured center to center: 21031 (3.9 mi, Cockeysville), 21111 (4.9 mi), 21013 (5.3 mi, Fallston), 21093 (5.4 mi, Timonium), 21057 (5.6 mi, Carney) and 21030 (5.9 mi, Cockeysville).

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