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Zip Code 21770 — Monrovia, MD

21770 is a ZIP Code associated with Monrovia, MD, located within Frederick. The postal region supports an estimated population of 8,751 residents across Data Pending housing units, with a population density of 295.1 people per square mile.

WorldPlaceData database updated: October 2026

📍 View location on OpenStreetMap (39.352450, -77.257910)

Data Metric	Local Statistic
Postal / Zip Code	21770
Primary City	Monrovia
State / Province	MD
County	Frederick
Total Population	8,751
Median Household Income	Data Pending
Total Housing Units	Data Pending
Population Density	295.1 people/sq mi
Timezone	America/New_York

How 21770 Compares

Metric	ZIP 21770	Frederick County	MD State Average
Population	8,751	300,100	6,205,597
Median Income	Data Pending	N/A	N/A
Population Density	295.1 /sq mi	--	--

Nearby ZIP Codes

ZIP Code	City	Distance	Population	Median Income
Zip 21754	Ijamsville	3.1 mi	8,156	N/A
Zip 21774	New Market	4.0 mi	17,134	N/A
Zip 20872	Damascus	4.8 mi	13,983	N/A
Zip 21771	Mount Airy	6.1 mi	33,031	N/A
Zip 21704	Frederick	6.2 mi	20,006	N/A

Data Sources & Methodology: Geographic coordinates and ZIP Code assignments are derived from underlying geographic and postal datasets. Note that ZIP Codes are USPS postal delivery areas, while Census ZCTAs are statistical approximation areas. Read full methodology →