21237 ZIP Code, Rosedale, MD
21237 is a ZIP code in Rosedale, Maryland — mostly in Baltimore County (94% of its land), with smaller parts in Baltimore city County. It covers 11 square miles of land. The closest ZIP codes are 21206, 21236 and 21214. 31,425 people live here in 12,417 households. At about 2,793 people per square mile it has suburban density, and owners and renters are mixed (62% own). Median household income is $91,693, below the Maryland median of $103,678.
Quick facts
- Mailing city: Rosedale, MD
- County: Baltimore County
- Land area: 11 sq mi
- Population: 31,425
- Median household income: $91,693
- Carrier routes: 21 (12,953 homes)
Key figures
| Measure | Value |
|---|---|
| Residents | 31,425 |
| Households | 12,417 |
| Median household income | $91,693 |
| Income per person | $42,796 |
| Median age | 41.8 |
| Homeowners | 62.1% |
| Median home value | $295,600 |
| Median rent | $1,606 |
| Bachelor's degree or higher | 26.5% |
| Average commute (minutes) | 28.7 |
| Households with kids under 18 | 26.8% |
| Moved in the past year | 14.2% |
| Below the poverty line | 8.1% |
| Broadband internet | 93.8% |
| Speak a non-English language at home | 20.7% |
Household income
| % of households | Value |
|---|---|
| <$10K | 4.3% |
| $10–15K | 1.2% |
| $15–25K | 3.4% |
| $25–35K | 4.8% |
| $35–50K | 10.0% |
| $50–75K | 17.8% |
| $75–100K | 11.5% |
| $100–150K | 26.0% |
| $150–200K | 11.1% |
| $200K+ | 9.8% |
Age
| % of all residents | Value |
|---|---|
| <10 | 8.5% |
| 10–19 | 12.1% |
| 20–24 | 5.2% |
| 25–34 | 13.2% |
| 35–44 | 14.9% |
| 45–54 | 13.7% |
| 55–64 | 13.6% |
| 65–74 | 11.3% |
| 75+ | 7.6% |
Tenure
| % of housing units | Value |
|---|---|
| Owned, with mortgage | 38.8% |
| Owned outright | 20.6% |
| Rented | 35.4% |
| Vacant | 5.3% |
Type of building
| % of housing units | Value |
|---|---|
| Detached house | 48.9% |
| Townhome | 16.4% |
| 2–4 units | 2.0% |
| 5–19 units | 24.8% |
| 20+ units | 7.2% |
| Mobile / other | 0.7% |
Businesses in 21237
841 business establishments with 18,680 employees (ZIP Codes Business Patterns 2023).
- Health Care and Social Assistance: 134
- Construction: 129
- Retail Trade: 118
- Wholesale Trade: 90
- Accommodation and Food Services: 70
- Other Services (except Public Administration): 65
- Professional, Scientific, and Technical Services: 49
- Administrative and Support and Waste Management and Remediation Services: 44
EDDM carrier routes
21237 has 21 USPS carrier routes with 12,953 residential and 955 business mailboxes. Open the EDDM route map.
Carrier routes in 21237
21237 has 21 USPS carrier routes (18 city (C), 3 rural (R)) with 12,953 residential and 955 business mailboxes. Routes range from 179 homes (C001) to 1,110 homes (C018); the median route has 611 homes. The Census counted 12,417 households in 21237 (2020–2024 average); USPS counts current mailboxes, including new and vacant homes.
| Homes per route | Routes |
|---|---|
| 1–249 | 2 |
| 250–499 | 3 |
| 500–749 | 10 |
| 750–999 | 5 |
| 1,000–1,499 | 1 |
| 1,500+ | 0 |
Best routes in 21237 for…
Most businesses
For B2B offers: office supplies, cleaning, IT, catering and commercial services.
- Route C001 — USPS business mailboxes 174, 179 homes
- Route R026 — USPS business mailboxes 168, 390 homes
- Route C024 — USPS business mailboxes 135, 466 homes
- Route C016 — USPS business mailboxes 133, 591 homes
- Route C004 — USPS business mailboxes 114, 504 homes
Select these 5 routes on the route map
Every carrier route in 21237
| Route | Type | Homes | Businesses | Est. median income | Est. owners | Est. families with kids | Est. moved in past year |
|---|---|---|---|---|---|---|---|
| C001 | City | 179 | 174 | — | — | — | — |
| C002 | City | 840 | 0 | $75,544 | — | — | — |
| C003 | City | 612 | 16 | $75,544 | — | — | — |
| C004 | City | 504 | 114 | $38,781 | — | — | — |
| C005 | City | 661 | 4 | $77,221 | — | — | — |
| C006 | City | 917 | 4 | $87,726 | — | — | — |
| C009 | City | 678 | 49 | $92,552 | — | — | — |
| C010 | City | 763 | 29 | $93,415 | — | — | — |
| C013 | City | 768 | 0 | $77,334 | — | — | — |
| C014 | City | 503 | 1 | $134,805 | — | — | — |
| C016 | City | 591 | 133 | — | — | — | — |
| C017 | City | 720 | 1 | $92,552 | — | — | — |
| C018 | City | 1,110 | 21 | $50,177 | — | — | — |
| C019 | City | 580 | 2 | $92,772 | — | — | — |
| C022 | City | 586 | 15 | $75,544 | — | — | — |
| C023 | City | 467 | 82 | $94,348 | — | — | — |
| C024 | City | 466 | 135 | $94,348 | — | — | — |
| C025 | City | 793 | 1 | $97,100 | — | — | — |
| R002 | Rural | 611 | 6 | $148,295 | — | — | — |
| R026 | Rural | 390 | 168 | $112,901 | — | — | — |
| R031 | Rural | 214 | 0 | $148,295 | — | — | — |
Income, owners, families and movers are estimates for each route (how we estimate them); mailbox counts are current USPS figures. Open 21237 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
- 21206 — Baltimore city, MD (2.3 mi)
- 21236 — Perry Hall CDP, MD (3.3 mi)
- 21214 — Baltimore city, MD (3.8 mi)
- 21234 — Carney CDP, MD (4.1 mi)
- 21205 — Baltimore city, MD (4.6 mi)
- 21221 — Essex CDP, MD (4.6 mi)
- 21251 — Baltimore city, MD (4.6 mi)
- 21213 — Baltimore city, MD (4.8 mi)
Areas that include 21237
- Rosedale, MD ZIP codes — 2 ZIP codes
- Rossville, MD ZIP codes — 2 ZIP codes
- White Marsh, MD ZIP codes — 4 ZIP codes
- Baltimore County ZIP codes — 54 ZIP codes
- Maryland ZIP code data
Where it ranks
Mail every home in 21237
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) 21237, which approximates the USPS ZIP code area. Census figures: American Community Survey 5-year estimates, 2020–2024.
Frequently asked questions
- What city is 21237 in?
- 21237 is a Rosedale, MD mailing address. By land area, 44% lies inside Rosedale, 38% lies inside Rossville, 10% lies inside White Marsh and 6% lies inside Baltimore.
- What county is 21237 in?
- 21237 is mostly in Baltimore County (94% of its land), with smaller parts in Baltimore city County.
- What is the population of 21237?
- About 31,425 people (±2,106), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 31,477.
- What is the median household income in 21237?
- $91,693 (±$11,145), 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 21237?
- 21 USPS carrier routes with 12,953 residential and 955 business mailboxes (13,908 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.
- What ZIP codes are near 21237?
- The closest, measured center to center: 21206 (2.3 mi, Baltimore), 21236 (3.3 mi, Perry Hall), 21214 (3.8 mi, Baltimore), 21234 (4.1 mi, Carney), 21205 (4.6 mi, Baltimore) and 21221 (4.6 mi, Essex).
This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.