Residential delivery area · Maryland
ZIP Code 21737: Glenelg, MD
ZIP code 21737 uses the postal name Glenelg, Maryland and lies entirely in Howard County (Census 2020 ZIP-county file). About 2,500 people live there (Census Bureau, ACS 2020-2024). Median household income is $250,000 or more (Census Bureau, ACS 2020-2024). Its land lies outside any incorporated or census-designated place.
- ACS2020-24
- Census2020
- FHFA2024
- ZBP2023
- IRS2022
- Town
- Glenelg · its only residential ZIP
- County
- Howard County
- Metro area
- Baltimore-Columbia-Towson, MD
- House district
- MD-3 119th Congress
- State
- Maryland
- Time zone
- Eastern
- Land area
- 5.1 sq mi · 483 people per sq mi
Where is ZIP code 21737?
21737 centers on 39.248°, -77.027° and covers 5.1 square miles of land plus 0.1 of water. It borders 5 ZIP codes: 21036, 21738, 20833, 21794, 21042.
The map draws ZIP code areas only. For the streets inside 21737, open its center on OpenStreetMap.
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries and the 2023 Gazetteer (2020 ZCTAs); ZIP-to-county shares, Census places and House districts (119th Congress) from the Census 2020 relationship files (shares of land); metro area from the OMB delineation (July 2023); town name and time zone from simplemaps US ZIP Codes (CC BY 4.0).
How does 21737 compare with the rest of Howard County?
| Measure | 21737 | In Howard County | In MD |
|---|---|---|---|
| People (ACS 2020-2024) | 2,474 | 22nd of 25 | 293rd of 477 |
| Median household income | $250k+ | 1= of 21 | 1= of 293 |
| Median home value | $996k | 2nd of 23 | 7th of 320 |
1= means a shared first place: 21737's median household income ties with 2 other ZIP codes at the Census cap in Howard County; median household income ties with 3 other ZIP codes at the Census cap in Maryland.
Its median household income is at the Census cap of $250,000 or more, like 117 other U.S. residential ZIP codes (69 of the 118 are large enough to rank), and it is denser than 72% of all U.S. residential ZIP codes. ZIP codes at the ACS caps ($250,000 or more for household income, $2,000,000 or more for home value) share the top rank.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B19013, B25077); ranks by PlainZIP over residential ZIP codes (ZCTAs).
How many people live in 21737?
The 2020 Census counted 2,318 people in 21737; the ACS, which samples households over 2020-2024, estimates 2,474. Between the 2010 and 2020 censuses its population grew 59.0% (its boundary stayed at least 90% the same).
- People, ACS 2020-2024
- 2,474±672 (90% margin)
- 2020 Census count
- 2,318+59.0% since 2010 (1,458)
- Households
- 739
- Median age
- 38.8
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B01002, B11001); 2020 Census (DHC P1); 2010 Census (SF1 P1).
Who lives in 21737?
Of the 2,474 people the ACS estimates in 21737, 24.5% are under 18 and 9.4% are 65 or older. The largest group by race and Hispanic origin is White (not Hispanic) (60.2%), then Asian (not Hispanic) (16.4%).
- Under 1824.5%
- 18 to 6466.2%
- 65 and older9.4%
- White, not Hispanic60.2%
- Asian, not Hispanic16.4%
- Black, not Hispanic11.6%
- Other or two or more11.5%
- Hispanic or Latino0.4%
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01001 age by sex, B03002 Hispanic or Latino origin by race); shares of the estimated population, small ZIP codes carry wide margins.
What do households in 21737 earn?
Median household income is $250,000 or more (ACS 2020-2024), the highest of the 21 ranked ZIP codes in Howard County.
- Median household income
- $250,000 or more
- Income per person
- $101,402
- Below the poverty line
- 0.2%
- Unemployed (of the labor force)
- 0.2%
- Adults 25+ with a bachelor's degree
- 75.8%
- Adjusted gross income per tax return, 2022
- $227,6971,010 returns; wages 66% of AGI (IRS)
Source: U.S. Census Bureau, ACS 2020-2024 and 2015-2019 5-year estimates (B19013, B19301, B17001, B23025, B15003; 2015-2019 dollars converted with the BLS CPI-U, 1.22699); IRS Statistics of Income, ZIP code data, tax year 2022 (adjusted gross income per return, filed under the address on the return).
What are homes worth in 21737?
- Median home value (owners' estimate)
- $996,400
- Median gross rent
- –
- Homes owned by their occupants
- 93.2%
- Housing units
- 739
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B25077, B25064, B25003, B25001); FHFA House Price Index, annual five-digit ZIP, updated 2026-03-31.
What businesses are in 21737?
83 business establishments had a location in this ZIP code in 2023, 10 more than in 2018; the most are in professional, scientific, and technical services (ZIP Code Business Patterns).
- Professional, scientific, and technical services28
- Retail trade7
- Health care and social assistance7
- Accommodation and food services7
- Construction5
- Administrative and support and waste management and remediation services5
Source: U.S. Census Bureau, ZIP Code Business Patterns 2023 and 2018 (establishments with paid employees, by the business's ZIP code).
Which ZIP codes are next to 21737?
| ZIP | Town | People | Household income | Distance |
|---|---|---|---|---|
| 21036 | Dayton | 2,569 | $218k | 1.4 mi |
| 21738 | Glenwood | 3,696 | $250k+ | 2.2 mi |
| 20833 | Brookeville | 7,860 | $204k | 3.2 mi |
| 21794 | West Friendship | 2,192 | $232k | 4.8 mi |
| 21042 | Ellicott City | 43,327 | $190k | 7.4 mi |
| 21029 | Clarksville | 13,607 | $244k | 4.3 mi (near) |
| 20862 | Brinklow | 430 | $190k | 4.7 mi (near) |
| 21723 | Cooksville | 669 | $241k | 5.7 mi (near) |
| 20777 | Highland | 3,221 | $226k | 5.9 mi (near) |
Source: PlainZIP from the Census 2020 ZCTA boundaries (shared edges) and internal points; figures ACS 2020-2024.