Gaithersburg, MD ZIP Codes
Gaithersburg, Maryland has 9 ZIP codes: 4 for street addresses (, , and ), 4 for PO boxes and 1 for a single organization.
Your street decides which one you use.
Which Gaithersburg ZIP code is my address in?
Street ranges from the Census Bureau, 2026. PO box and organization ZIP codes are not found by street. A new street may be missing: address not found?
Gaithersburg ZIP code map
Tap or point to an area to see its ZIP code.Full-size map
20883, 20884, 20885, 20898 and 20899 have no area on the map: they are PO box or single-organization ZIP codes. Dashed line: Gaithersburg city limits.
Map: Census Bureau ZIP Code Tabulation Areas (2020) and place limits (2024).
All Gaithersburg ZIP codes by type
| ZIP | Type and post office or station |
|---|---|
| 20877 | street delivery Gaithersburg |
| 20878 | street delivery Diamond Farms |
| 20879 | street delivery Montgomery Village |
| 20882 | street delivery Damascus |
| 20883 | PO boxes at the Kentlands post office Kentlands |
| 20884 | PO boxes at the Gaithersburg post office Gaithersburg |
| 20885 | PO boxes at the Diamond Farms post office Diamond Farms |
| 20898 | PO boxes at the Suburban Window Scv post office Suburban Window Scv |
| 20899 | one organization Suburban Maryland |
Why your mail may say Gaithersburg when you live outside it
Gaithersburg ZIP codes also cover Damascus, North Potomac and Darnestown, so a letter addressed to Gaithersburg can go to a home outside the city limits.
A ZIP code does not set your city, school district or tax. Montgomery County property records show which city you are in.
Gaithersburg ZIP code questions
What is the main ZIP code for Gaithersburg?
20877, the ZIP code of the main Gaithersburg post office at 21 S Summit Ave.
Which Gaithersburg ZIP codes are for PO boxes only?
20883, 20884, 20885 and 20898. Mail to them goes to boxes at the post office, not to street addresses.
What county is Gaithersburg in?
Montgomery County.
ZIP codes for towns near Gaithersburg
More towns near Gaithersburg: North Bethesda, Potomac, Wheaton, Bethesda, Silver Spring, McLean, Sterling, Reston, Ashburn.
Sources and last checked
USPS ZIP Locale Detail (October 1, 2026), GeoNames (CC BY 4.0), U.S. Census Bureau, HUD-USPS crosswalk.
Checked October 20, 2026. Sources · How we build our lists · Corrections