🇺🇸 United States ZIP Code

STANDARD

21555

Oldtown

ZIP Code 21555 is a standard zip code serving Oldtown, Oldtown, Maryland (MD), in Allegany County, United States. It has an estimated population of 1,936 with a median household income of $56,042. The area falls within the America/New_York timezone.

Median Household Income vs. National Average

Location

Country: 🇺🇸 United States
State / Province: Maryland (MD)
County: Allegany
City: Oldtown
Timezone: America/New_York

Coordinates

Latitude: 39.584600
Longitude: -78.604400

Geographic Details

Land Area: 105.96 mi²
Water Area: 2.27 mi²
Population Density: 18.0 people per mi² (20th percentile)
Bounding Box: 39.669101°N, 39.515916°S, -78.394801°E, -78.725650°W

With 1,936 residents spread across 105.96 square miles, this area has a population density of 18.0 people per square mile.

Demographics

1,936

Population

40th percentile

$56,042

Median Income

65th percentile

$155,600

Median Home Value

60th percentile

105.96 mi²

Land Area

The median household income in 21555 is $56,042, and the median home value is $155,600.

Housing

1,054

Total Units

776

Occupied Units

73.6%

Occupancy Rate

Similar ZIP Codes in Maryland

ZIP codes with similar median household income in Maryland.

21849

Parsonsburg

$51,729

21601

Easton

$57,875

21224

Baltimore

$55,085

21636

Goldsboro

$60,926

21536

Grantsville

$49,271

21649

Marydel

$50,658

20609

Avenue

$53,203

21850

Pittsville

$54,103

Frequently Asked Questions

What information is available for each ZIP code?

Each ZIP code page shows city, state, county, geographic coordinates, timezone, population, median household income, median home value, housing units, land area, population density, commute time, educational attainment, area codes, and ZIP code type (Standard, PO Box, or Unique).

What are the different types of ZIP codes?

There are three types of ZIP codes: Standard (residential and commercial delivery areas), PO Box (assigned to post office box sections), and Unique (assigned to a single high-volume address like a government agency or large company). Standard ZIP codes are the most common.

How often is ZIP code data updated?

ZIP code assignments are updated quarterly by the USPS. Demographic data comes from the US Census Bureau's American Community Survey (ACS), which releases new 5-year estimates annually. ZipFYI updates its data to reflect the latest available information.

What is population density and why does it matter?

Population density measures the number of people per square mile in a ZIP code area. It helps identify urban vs. rural areas, affects real estate values, impacts service availability, and is used in market analysis. Dense urban ZIP codes may have 50,000+ people per square mile.

How are ZIP code boundaries determined?

ZIP code boundaries are determined by the USPS based on mail delivery routes, not political or geographic boundaries. They follow carrier routes and may cross city, county, or even state lines. Boundaries can change when the USPS reorganizes delivery operations.

What does median household income tell me about a ZIP code?

Median household income is the middle value when all household incomes in a ZIP code are sorted. Half of households earn more and half earn less. It is a better indicator of typical earnings than average income, which can be skewed by very high or very low outliers.