Glen Arm, MD · standard
ZIP Code 21057
Baltimore County, Maryland - Census ACS demographics, housing tenure, and business patterns, benchmarked against every US ZIP.
- 4,112
- 95/sq mi Moderate-density area
- $145,924
- Median income Above-median income area
- $623,200
- Median home value Above-median home value
- 54.0%
- Bachelor's or higher Above-average bachelor's attainment
National ZIP placement
Glen Arm pairs a top-decile household income with top-decile home values, in a rural, homeowner-dominated area.
- Top 4%
- household income, US ZIPs
- Top 8%
- home value, US ZIPs
- 95
- people per sq mi
- 85%
- owner-occupied homes
Source: U.S. Census Bureau ACS 5-Year Estimates (2019–2023). Percentiles rank ZIP 21057 against every reporting US ZIP.
ZIP code 21057 covers 43.5 square miles in Glen Arm, Baltimore County, Maryland (a standard USPS delivery area), with a modest 4,112 residents on file, a density of 95 people per square mile, in the New York time zone.
ZIP 21057 skews affluent, with a median household income of $145,924 (28% above the average Maryland ZIP), while per-capita income is $61,920. Both reported hardship measures are comparatively low in absolute terms: poverty is 3.1% and unemployment is 1.7%. Housing is both higher-cost and owner-heavy: median home value is $623,200 (39% above the average Maryland ZIP), while 85.1% of occupied homes are owner-occupied and median rent is $1,746.
This is a highly-educated ZIP: 54.0% of adults hold a bachelor's degree or higher, the median age is 41.3, and the average commute is 33 minutes. The page also surfaces 10 ZIP codes within roughly 10 miles and 6 more in Baltimore County, so 21057 can be compared with both its immediate and county-level context.
Every figure on this page is sourced from the U.S. Census Bureau American Community Survey 5-Year Estimates (including median rent) and the FHFA House Price Index, no estimates, no proprietary scoring. Verify with Census →
Top industries in ZIP 21057
Top 5 sectors by establishment count in Glen Arm, MD
Which industries have the most business establishments in ZIP 21057.
- Construction
Construction
29 establishments
- Professional, scientific, and technical services
Professional, scientific, and technical services
14 establishments
- Other services (except public administration)
Other services (except public administration)
12 establishments
- Administrative and support and waste management and remediation services 8
Administrative and support and waste management and remediation services
8 establishments
- Retail trade 7
Retail trade
7 establishments
What this shows Establishment counts come from the Census ZIP Code Business Patterns program, which counts physical business locations rather than employees or revenue.
Source: U.S. Census Bureau, American Community Survey 5-Year Estimates + ZIP Code Business Patterns + FHFA HPI ACS demographics and median rent, ZBP business establishments, FHFA HPI for ZIP 21057, Glen Arm, MD · 2023 Census ACS 5-Year Estimates use a rolling 60-month sample for stable small-geography estimates; ZBP updated annually; FHFA HPI updated quarterly/annually.
Quick Facts
4,112
Population
43.5
Area (sq mi)
95
People / sq mi
New York
Time Zone
standard
ZIP Type
Who lives in ZIP 21057?
41.3
Median Age
49.5%
Male
50.5%
Female
4.1%
Foreign-Born
Hispanic or Latino is an ethnicity category from the Census Bureau and may overlap with other categories above.
Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)
How much do residents earn?
$145,924
Median Household Income
+28% vs state ZIP avg
$61,920
Per Capita Income
3.1%
Poverty Rate
1.7%
Unemployment Rate
32.7 min
Mean Commute Time
How ZIP 21057 ranks among Maryland ZIPs
Glen Arm, MD household income vs. every Maryland ZIP code
Median household income among 419 reporting Maryland ZIPs (this ZIP's population is too small for a reliable national-corpus placement)
$145,924 Top 21% higher than 79% of 419 Maryland ZIPs
Each bar is a $20K-wide band; taller bars hold more Maryland ZIPs. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source U.S. Census Bureau, ACS 5-Year Estimates · 2019–2023
Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)
What is the education profile here?
Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)
What does housing look like?
Housing stock: occupied vs vacant
1,603housing units
1,603
Total Housing Units
1,545
Occupied Units
58
Vacant Units
2.82
Avg Household Size
Occupancy Type
$623,200
Median Home Value
+39% vs state ZIP avg
$1,746
Median Rent
1970
Median Year Built
Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)
How have home values changed over time?
FHFA House Price Index, annual appreciation data based on repeat sales and appraisals
-0.3%
YoY Change (2024)
209
HPI Index (2000 = 100)
+109%
Total Change Since 2000
Home values in ZIP 21057 have decreased 0.3% over the past year (2024). Since 2000, this ZIP has seen +109% cumulative appreciation.
| Year | Annual Change | HPI Index |
|---|---|---|
| 2020 | +2.1% | 163 |
| 2021 | +5.0% | 171 |
| 2022 | +14.6% | 196 |
| 2023 | +6.9% | 210 |
| 2024 | -0.3% | 209 |
Source: Federal Housing Finance Agency (FHFA) House Price Index, All-Transactions, Five-Digit ZIP Codes (Developmental Index). Index base = 100 in year 2000. Data through 2024. ZIP codes with few transactions may show missing values.
What businesses operate in this ZIP?
Census Bureau data shows 110 business establishments in ZIP 21057, employing approximately 879 people with a combined annual payroll of $51,451,000.
110
Businesses
879
Employees
$51.5M
Annual Payroll
12
Industry Sectors
| Industry | Establishments | % of Total |
|---|---|---|
| Construction | 29 | 26.4% |
| Professional, scientific, and technical services | 14 | 12.7% |
| Other services (except public administration) | 12 | 10.9% |
| Administrative and support and waste management and remediation services | 8 | 7.3% |
| Retail trade | 7 | 6.4% |
| Wholesale trade | 6 | 5.5% |
| Finance and insurance | 6 | 5.5% |
| Real estate and rental and leasing | 5 | 4.5% |
| Health care and social assistance | 5 | 4.5% |
| Arts, entertainment, and recreation | 5 | 4.5% |
| Manufacturing | 3 | 2.7% |
| Accommodation and food services | 3 | 2.7% |
Source: U.S. Census Bureau, ZIP Code Business Patterns (ZBP), 2023. Employment figures may include noise for disclosure avoidance.
Nearby ZIP Codes
Want a side-by-side? Compare 21057 vs 21082 →
ZIP 21057 vs its nearest neighbors, by population
Resident population of this ZIP and the closest reporting ZIP codes within ~10 miles.
- 21234
Parkville (21234)
69,752 residents
- 21236
Nottingham (21236)
38,474 residents
- 21237
Rosedale (21237)
30,059 residents
- 21286 19,206
Towson (21286)
19,206 residents
- 21128 12,802
Perry Hall (21128)
12,802 residents
- 21131 7,253
Phoenix (21131)
7,253 residents
- 21087 5,451
Kingsville (21087)
5,451 residents
- 21013 4,653
Baldwin (21013)
4,653 residents
- 21057 4,112
Glen Arm (21057)
4,112 residents
What this shows Among its immediate neighbors, ZIP 21057 ranks #9 by population - useful context the national average alone can't give.
ZIP 21057 vs its nearest neighbors, by median income
Median household income of this ZIP and the closest reporting ZIP codes within ~10 miles.
- 21051
Fork (21051)
$232,721 median income
- 21131
Phoenix (21131)
$197,619 median income
- 21013
Baldwin (21013)
$171,354 median income
- 21057
Glen Arm (21057)
$145,924 median income
- 21082
Hydes (21082)
$145,571 median income
- 21087
Kingsville (21087)
$129,188 median income
- 21128
Perry Hall (21128)
$128,069 median income
- 21236
Nottingham (21236)
$95,149 median income
- 21286
Towson (21286)
$93,808 median income
What this shows By household income, ZIP 21057 ranks #4 of 9 neighboring ZIPs, local affluence varies block to block, not just metro to metro.
| ZIP Code | City | Population | Distance |
|---|---|---|---|
| 21082 | Hydes, MD | 654 | 2.5 mi |
| 21051 | Fork, MD | 279 | 3.2 mi |
| 21013 | Baldwin, MD | 4,653 | 4.2 mi |
| 21236 | Nottingham, MD | 38,474 | 4.4 mi |
| 21234 | Parkville, MD | 69,752 | 4.2 mi |
| 21087 | Kingsville, MD | 5,451 | 4.8 mi |
| 21128 | Perry Hall, MD | 12,802 | 4.4 mi |
| 21286 | Towson, MD | 19,206 | 4.4 mi |
| 21131 | Phoenix, MD | 7,253 | 5.2 mi |
| 21237 | Rosedale, MD | 30,059 | 7.7 mi |
Nationwide ZIPs with similar ACS profiles
Two Census-derived peer sets for ZIP 21057, both outside MD so the neighborhoods are not geographic containment (Nearby and same-county blocks stay local).
Similar population
Nearest cross-state ZIPs by resident population (4,112 here; floor ≥1,000).
Similar median household income
Nearest cross-state ZIPs by ACS median household income.
More ZIP Codes in Baltimore County
Related Areas
Frequently Asked Questions
What county is ZIP code 21057 in?
ZIP code 21057 (Glen Arm) is located in Baltimore County, Maryland. Baltimore County contains multiple ZIP codes, see the full list at /counties/baltimore-md-24005.
What is the population of ZIP code 21057?
ZIP code 21057 in Glen Arm, MD has a population of 4,112 according to the Census Bureau ACS 2023 estimates.
What is the median household income in ZIP 21057?
The median household income in ZIP 21057 is $145,924, which is 91% above the national average of $76,288.
What is the average home value in ZIP 21057?
The median home value in ZIP 21057 is $623,200, which is 124% above the national average of $278,155.
What is the demographic makeup of ZIP 21057?
The largest racial group in ZIP 21057 is White at 88.1%. Hispanic or Latino residents make up 7.1% of the population.
How many businesses are in ZIP code 21057?
ZIP code 21057 has 110 business establishments employing approximately 879 people, according to Census Bureau ZIP Code Business Patterns (ZBP) 2023 data.
What are the main industries in ZIP code 21057?
The top industries by establishment count in ZIP 21057 are: Construction (29), Professional, scientific, and technical services (14), Other services (except public administration) (12). There are 12 industry sectors represented in total.
How have home values changed in ZIP code 21057?
According to the FHFA House Price Index, home values in ZIP 21057 decreased by 0.3% in 2024. Since 2000, home values in this ZIP have appreciated by approximately 109%. This is a developmental index based on repeat sales and appraisal data from Fannie Mae and Freddie Mac.
What is the education level in ZIP code 21057?
In ZIP code 21057, 67.9% of residents aged 25+ have a high school diploma or higher, and 54.0% hold a bachelor's degree or higher. These figures come from the Census Bureau ACS 5-Year Estimates (2023).
What is the average commute time in ZIP 21057?
The mean commute time for workers in ZIP code 21057 is 32.7 minutes according to Census ACS data. The national average is roughly 26 minutes, so commuters here spend more time traveling to work than typical.
What percentage of residents own vs. rent in ZIP 21057?
In ZIP code 21057, approximately 85.1% of occupied housing units are owner-occupied and 14.9% are renter-occupied, based on Census ACS 2023 data.
What is the poverty rate in ZIP code 21057?
The poverty rate in ZIP code 21057 is 3.1% according to Census Bureau ACS 2023 estimates. This measures the percentage of the population living below the federal poverty threshold.
Related
Take this with you
What to do with ZIP 21057's numbers, next.
- See how ZIP 21057 compares to a neighboring ZIP code on the same Census fields Compare this ZIP
- Check where Glen Arm, MD ranks among every U.S. ZIP code on income, education, or homeownership View national rankings
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ZIP Code Tabulation Areas (ZCTAs) are Census Bureau approximations of USPS ZIP codes; figures describe the ZCTA area, not any single address within it.