ZIP CodesZIP codes in St. Mary's County, Maryland
St. Mary's County, Maryland has 29 ZIP codes in this list, from 20606 to 20692. They cover 29 places, among them Abell, Avenue, Bushwood and California.
Nothing in this county matches.
The ZIP code areas of St. Mary's County add up to about 393 square miles of land (1,018 sq km) as the Census Bureau draws them. The largest is 20659 (Mechanicsville), with 97.0 square miles.
Using these codes
- In an address, the ZIP code comes last, after the city and the two-letter state: Abell, MD 20606.
- 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.