PlainZIP

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
$145,924
Median income
$623,200
Median home value
54.0%
Bachelor's or higher

The verdict

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 Maryland average), while per-capita income is $61,920. The poverty rate stands at 3.1% and the unemployment rate at 1.7%. Housing costs here run $623,200 for a typical home value (39% above the state average), with rent averaging $1,746 a month; 85.1% of homes are owner-occupied.

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. A geography-based comparison follows: 10 ZIP codes within about 10 miles of 21057, plus 6 more within Baltimore County, give a clearer read than the national average alone.

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.

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 · ZIP Code Business Patterns (ZBP) As of 2023

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

Neighborhood Scorecard
Get an A-F grade across income, safety, housing, rent, education, commute, and childcare for this ZIP code.
View Scorecard →

Who lives in ZIP 21057?

41.3

Median Age

49.5%

Male

50.5%

Female

4.1%

Foreign-Born

White 88.1%
African American 4.6%
Asian 1.5%
American Indian or Alaska Native 0.3%
Native Hawaiian or Pacific Islander 0.0%
Two or More Ethnicities 4.4%
Hispanic or Latino 7.1%

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

$61,920

Per Capita Income

3.1%

Poverty Rate

1.7%

Unemployment Rate

32.7 min

Mean Commute Time

How ZIP 21057 ranks nationally

Glen Arm, MD household income vs. every US ZIP code

Median household income, the full national distribution, with this ZIP marked

$145,924 Top 4% higher than 96% of 30,318 US ZIPs

$0–$20,000: 118 US ZIPs (0%). Below this entry. $20,000–$40,000: 1,573 US ZIPs (5%). Below this entry. $40,000–$60,000: 7,092 US ZIPs (23%). Below this entry. $60,000–$80,000: 9,980 US ZIPs (33%). Below this entry. $80,000–$100,000: 5,778 US ZIPs (19%). Below this entry. $100,000–$120,000: 2,855 US ZIPs (9%). Below this entry. $120,000–$140,000: 1,362 US ZIPs (4%). Below this entry. $140,000–$160,000: 686 US ZIPs (2%). This entry sits in this band. $160,000–$180,000: 364 US ZIPs (1%). Above this entry. $180,000–$200,000: 186 US ZIPs (1%). Above this entry. $200,000–$220,000: 324 US ZIPs (1%). Above this entry. This ZIP $0 $200K+ every reporting US ZIP, bucketed by value

Each bar is a $20K-wide band; taller bars hold more US 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?

High School Graduate or Higher 67.9%
Bachelor's Degree or Higher 54.0%

Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)

What does housing look like?

1,603

Total Housing Units

1,545

Occupied Units

58

Vacant Units

2.82

Avg Household Size

Occupancy Type

Owner 85.1%
Renter 14.9%

$623,200

Median Home Value

+39% vs state

$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.

residents

What this shows Among its immediate neighbors, ZIP 21057 ranks #9 by population - useful context the national average alone can't give.

Source U.S. Census Bureau · ACS 5-Year Estimates As of 2019–2023

ZIP 21057 vs its nearest neighbors, by median income

Median household income of this ZIP and the closest reporting ZIP codes within ~10 miles.

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.

Source U.S. Census Bureau · ACS 5-Year Estimates As of 2019–2023
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

More ZIP Codes in Baltimore County

21234 standard
Parkville, MD
Pop: 69,752
21222 standard
Dundalk, MD
Pop: 55,786
21117 standard
Owings Mills, MD
Pop: 53,778
21207 standard
Gwynn Oak, MD
Pop: 48,133
21228 standard
Catonsville, MD
Pop: 47,577
21221 standard
Essex, MD
Pop: 42,154

Related Areas

Baltimore County Glen Arm, MD Maryland

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.

Read our methodology to see how this data is sourced, computed, and verified.