ZIP CodesZIP codes in Frederick County, Maryland
Frederick County, Maryland has 31 ZIP codes in this list, from 21701 to 21798. They cover 26 places, among them Frederick, Adamstown, Braddock Heights and Brunswick.
Nothing in this county matches.
The ZIP code areas of Frederick County add up to about 634 square miles of land (1,643 sq km) as the Census Bureau draws them. The largest is 21771 (Mount Airy), with 89.5 square miles.
Places with more than one code here: Frederick (6 codes).
Using these codes
- In an address, the ZIP code comes last, after the city and the two-letter state: Frederick, MD 21701.
- Tap a ZIP code to open it in the look-up, with a copy button for the address line.
- A code can cross a county line, and one town can have several codes. The table shows the main place of each code.
- "No area" means the Census Bureau draws no area for that code. Such codes are usually for post office boxes or a single building.
Places and counties: GeoNames. Areas: U.S. Census Bureau, 2024 ZIP Code Tabulation Areas. Checked in November 2026. This site is not connected with the United States Postal Service; for mailing, confirm the address with USPS.