Residential delivery area · Maryland
ZIP Code 21784: Eldersburg (Sykesville), MD
ZIP code 21784 is in Eldersburg (postal name Sykesville), Maryland, mostly in Carroll County (82% of its land) with the rest in Howard County (Census 2020 ZIP-county file). About 39,000 people live there (Census Bureau, ACS 2020-2024). Median household income is $139,395 (Census Bureau, ACS 2020-2024). By Census place, its land lies in Eldersburg (59%) and Sykesville (3%); 38% is outside any Census place.
- ACS2020-24
- Census2020
- FHFA2025
- ZBP2023
- IRS2022
- Town
- Sykesville · its only residential ZIP
- County
- Carroll County (82%); Howard County (18%)
- Census places
- Eldersburg (59%) census-designated place; Sykesville (3%)
- Neighborhoods
- Carroll Fields, Hawk Ridge, Lexington Run, Shannon Run GeoNames
- Metro area
- Baltimore-Columbia-Towson, MD
- House districts
- MD-2 (57%), MD-3 (43%) 119th Congress, by share of land
- State
- Maryland
- Time zone
- Eastern
- Land area
- 56.1 sq mi · 699 people per sq mi
Where is ZIP code 21784?
21784 centers on 39.401°, -76.974° and covers 56.1 square miles of land plus 2.0 of water. It borders 7 ZIP codes: 21104, 21723, 21797, 21794, 21048, 21136, 21157.
The map draws ZIP code areas only. For the streets inside 21784, 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); neighborhoods from the GeoNames gazetteer (CC BY 4.0), placed in this ZIP code by PlainZIP.
How does 21784 compare with the rest of Carroll County?
| Measure | 21784 | In Carroll County | In MD |
|---|---|---|---|
| People (ACS 2020-2024) | 39,258 | 1st of 15 | 45th of 477 |
| Median household income | $139k | 4th of 15 | 74th of 293 |
| Median home value | $492k | 4th of 15 | 96th of 320 |
Its median household income is higher than in 95% of U.S. residential ZIP codes, and it is denser than 75% 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 21784?
The 2020 Census counted 40,028 people in 21784; the ACS, which samples households over 2020-2024, estimates 39,258. Between the 2010 and 2020 censuses its population grew 5.5% (its boundary stayed at least 90% the same).
- People, ACS 2020-2024
- 39,258
- 2020 Census count
- 40,028+5.5% since 2010 (37,941)
- Households
- 13,416
- Median age
- 38.9
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 21784?
Of the 39,258 people the ACS estimates in 21784, 25.3% are under 18 and 15.8% are 65 or older. The largest group by race and Hispanic origin is White (not Hispanic) (77.0%).
- Under 1825.3%
- 18 to 6458.9%
- 65 and older15.8%
- White, not Hispanic77.0%
- Hispanic or Latino6.8%
- Black, not Hispanic6.6%
- Other or two or more5.4%
- Asian, not Hispanic4.1%
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 21784 earn?
Median household income is $139,395 (ACS 2020-2024), the 4th highest of the 15 ranked ZIP codes in Carroll County. It is not measurably different from 2015-2019 ($143,938 in 2024 dollars): the change is within the surveys' margins of error.
- Median household income
- $139,395
- Income per person
- $56,974
- Below the poverty line
- 4.4%
- Unemployed (of the labor force)
- 3.7%
- Adults 25+ with a bachelor's degree
- 53.0%
- Adjusted gross income per tax return, 2022
- $119,88619,810 returns; wages 74% 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 21784?
FHFA's house price index for 21784, built from repeat sales and appraisals of the same homes, rose 60% from 2015 to 2025 and rose 41% from 2020 to 2025, and moved +3.1% in 2025.
- Median home value (owners' estimate)
- $491,800
- Median gross rent
- $1,739
- Homes owned by their occupants
- 87.3%
- Housing units
- 13,797
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 21784?
975 business establishments had a location in this ZIP code in 2023, 66 more than in 2018; the most are in construction (ZIP Code Business Patterns).
- Construction153
- Health care and social assistance131
- Professional, scientific, and technical services130
- Other services (except public administration)105
- Retail trade101
- Accommodation and food services76
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 21784?
| ZIP | Town | People | Household income | Distance |
|---|---|---|---|---|
| 21104 | Marriottsville | 6,052 | $192k | 5.0 mi |
| 21723 | Cooksville | 669 | $241k | 5.2 mi |
| 21797 | Woodbine | 8,643 | $189k | 7.0 mi |
| 21794 | West Friendship | 2,192 | $232k | 7.1 mi |
| 21048 | Finksburg | 10,481 | $132k | 7.3 mi |
| 21136 | Reisterstown | 32,088 | $119k | 7.4 mi |
| 21157 | Westminster | 38,984 | $105k | 10.2 mi |
| 21163 | Woodstock | 7,539 | $135k | 8.0 mi (near) |
| 21133 | Randallstown | 31,398 | $81k | 8.8 mi (near) |
Source: PlainZIP from the Census 2020 ZCTA boundaries (shared edges) and internal points; figures ACS 2020-2024.