Residential delivery area · Maryland
ZIP Code 21723: Cooksville, MD
ZIP code 21723 uses the postal name Cooksville, Maryland and lies entirely in Howard County (Census 2020 ZIP-county file). About 670 people live there (Census Bureau, ACS 2020-2024). Median household income is $241,250 (Census Bureau, ACS 2020-2024). Its land lies outside any incorporated or census-designated place.
- ACS2020-24
- Census2020
- FHFA2025
- ZBP2023
- IRS2022
- Town
- Cooksville · 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
- 3.6 sq mi · 186 people per sq mi
Where is ZIP code 21723?
21723 centers on 39.329°, -77.003° and covers 3.6 square miles of land plus 0.0 of water. It borders 4 ZIP codes: 21794, 21797, 21738, 21784.
The map draws ZIP code areas only. For the streets inside 21723, 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 21723 compare with the rest of Howard County?
| Measure | 21723 | In Howard County | In MD |
|---|---|---|---|
| People (ACS 2020-2024) | 669 | 24th of 25 | 376th of 477 |
| Median household income | $241k | not ranked | not ranked |
| Median home value | $1.01M | not ranked | not ranked |
21723's income and home value are not ranked: it has fewer than 1,000 residents (669). Rankings use ZIP codes of 1,000 or more people living in households, with margins at most 25% of the figure.
It is denser than 62% of 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 21723?
The 2020 Census counted 937 people in 21723; the ACS, which samples households over 2020-2024, estimates 669. Its boundary changed between the 2010 and 2020 censuses, so the two counts are not compared.
- People, ACS 2020-2024
- 669±221 (90% margin)
- 2020 Census count
- 937
- Households
- 232
- Median age
- 48.3
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 21723?
Of the 669 people the ACS estimates in 21723, 20.8% are under 18 and 10.0% are 65 or older. The largest group by race and Hispanic origin is Asian (not Hispanic) (46.8%), then White (not Hispanic) (31.8%).
- Under 1820.8%
- 18 to 6469.2%
- 65 and older10.0%
- Asian, not Hispanic46.8%
- White, not Hispanic31.8%
- Black, not Hispanic14.9%
- Other or two or more6.4%
- Hispanic or Latino0.0%
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 21723 earn?
Median household income is $241,250 (ACS 2020-2024).
- Median household income
- $241,250±$148,336
- Income per person
- $72,952
- Below the poverty line
- 0.0%
- Unemployed (of the labor force)
- 0.0%
- Adults 25+ with a bachelor's degree
- 82.3%
- Adjusted gross income per tax return, 2022
- $249,795440 returns; wages 55% 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 21723?
FHFA's house price index for 21723, built from repeat sales and appraisals of the same homes, rose 51% from 2015 to 2025 and rose 38% from 2020 to 2025.
- Median home value (owners' estimate)
- $1,005,500
- Median gross rent
- –
- Homes owned by their occupants
- 95.3%
- Housing units
- 232
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 21723?
22 business establishments had a location in this ZIP code in 2023, 5 more than in 2018; the most are in professional, scientific, and technical services (ZIP Code Business Patterns).
- Professional, scientific, and technical services7
- Construction3
- Retail trade3
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 21723?
| ZIP | Town | People | Household income | Distance |
|---|---|---|---|---|
| 21794 | West Friendship | 2,192 | $232k | 2.9 mi |
| 21797 | Woodbine | 8,643 | $189k | 3.5 mi |
| 21738 | Glenwood | 3,696 | $250k+ | 3.6 mi |
| 21784 | Sykesville | 39,258 | $139k | 5.2 mi |
| 21104 | Marriottsville | 6,052 | $192k | 5.0 mi (near) |
| 21737 | Glenelg | 2,474 | $250k+ | 5.7 mi (near) |
| 21036 | Dayton | 2,569 | $218k | 6.5 mi (near) |
| 21042 | Ellicott City | 43,327 | $190k | 6.8 mi (near) |
Source: PlainZIP from the Census 2020 ZCTA boundaries (shared edges) and internal points; figures ACS 2020-2024.