🇺🇸 United States ZIP Code

STANDARD

20878

Gaithersburg

ZIP Code 20878 is a standard zip code serving Gaithersburg, Gaithersburg, Maryland (MD), in Montgomery County, United States. It has an estimated population of 62,446 with a median household income of $116,347. The area falls within the America/New_York timezone.

Median Household Income vs. National Average

Location

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

Coordinates

Latitude: 39.112500
Longitude: -77.251500

Geographic Details

Land Area: 21.83 mi²
Water Area: 0.44 mi²
Population Density: 2860.0 people per mi² (85th percentile)
Bounding Box: 39.161293°N, 39.063503°S, -77.187583°E, -77.302856°W

With 62,446 residents spread across 21.83 square miles, this area has a population density of 2860.0 people per square mile.

Demographics

62,446

Population

95th percentile

$116,347

Median Income

95th percentile

$525,300

Median Home Value

95th percentile

21.83 mi²

Land Area

The median household income in 20878 is $116,347, and the median home value is $525,300. This places the area in the top 25% nationally for household income.

Housing

23,155

Total Units

22,268

Occupied Units

96.2%

Occupancy Rate

Nearby ZIP Codes

Other zip codes in Gaithersburg, MD.

20877

Gaithersburg

20879

Gaithersburg

20882

Gaithersburg

20883

Gaithersburg

20884

Gaithersburg

20885

Gaithersburg

20898

Gaithersburg

20899

Gaithersburg

Similar ZIP Codes in Maryland

ZIP codes with similar median household income in Maryland.

21114

Crofton

$107,715

20607

Accokeek

$123,851

21046

Columbia

$104,535

21013

Baldwin

$104,089

20905

Silver Spring

$116,806

20814

Bethesda

$114,577

21054

Gambrills

$119,009

20815

Chevy Chase

$131,994

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.