In which county is ZIP code 21770 located?

ZIP 21770 is listed under Frederick, MD.

When was this page updated?

This page was updated on 2026-01-08.

ZIP Code 21770: Monrovia, MD

ZIP: 21770

County: Frederick

Coordinates: 39.35120, -77.24940

ZIP Type: Standard

Time Zone: Eastern Time (ET)

Get a reliable snapshot of the Monrovia, MD postal area 21770. This page summarizes county, coordinates, and local facts to help with services and location research.

Primary City	Monrovia
ZIP Code	21770
County	Frederick
State	MD
Latitude / Longitude	39.35120, -77.24940
ZIP Type	Standard
Time Zone	Eastern Time (ET)
Data Updated	2026-01-08

Maps & Useful Links

Open in Maps: Google Maps · OpenStreetMap

These links show the approximate center point for ZIP 21770 (not an exact boundary).

Geographic & Administrative Context

For mapping and verification, 21770 is commonly represented around 39.35120, -77.24940. These coordinates help identify the general area within Frederick, MD.

Local Coverage Notes

ZIP codes can cover multiple neighborhoods and unincorporated areas. Use ZIP 21770 for mail delivery and general location reference in Frederick, MD.

Some addresses near Monrovia may share this ZIP due to delivery routing and local service areas.

Related ZIP Codes (Nearby)

Explore other postal codes near Monrovia within MD.

Frequently Asked Questions

What is the primary city for ZIP code 21770?

The primary city for this ZIP code is Monrovia, located in MD.

In which county is 21770 located?

ZIP code 21770 is situated within Frederick, MD.

What are the coordinates for 21770?

The approximate center point is 39.35120 (Latitude) and -77.24940 (Longitude).

Is ZIP code 21770 active?

This page lists ZIP 21770 as Listed based on the latest refresh date shown above.

Does ZIP 21770 cover multiple areas?

Yes. Many ZIP codes cover multiple neighborhoods or nearby areas. For exact boundaries, use official mapping tools.

Methodology & Data Notes

How we build this page: We generate this page from a structured ZIP dataset and refresh key fields (city, county, and coordinates) during scheduled updates. Coordinates represent an approximate center point, not an official boundary map.
Sources: Public ZIP reference datasets and geographic coordinate references. If you use specific sources (e.g., USPS, Census), list them on your About/Methodology page.

Page updated: 2026-01-08