City · Maryland · United States
Rocky Ridge, MD — ZIP codes
1 ZIP code · Frederick County
- City
- Rocky Ridge
- County
- Frederick
- State
- Maryland
- Country
- United States
- Postal code
- 21778Single source
- Coordinates
- 39.6057, -77.3296 View on OpenStreetMap
- Area codes
- 240, 227, 301 (from the nearest rate centre)
ZIP codes (1)
| Postal code | Place name | Verification |
|---|---|---|
| 21778 | Rocky Ridge | Single source |
Sources and verification
US ZIP codes have five digits. They are postal routing areas, not administrative boundaries: a ZIP can span more than one city or county, and the city shown is the primary USPS name for that code.
GeoNames · U.S. Census Bureau (ACS) · U.S. Census Bureau · NOAA NCEI · usda-phzm. Last generated : 2026-08-21. Report an error.