ZIP Codes in Rockville, MD
Rockville uses 4 ZIP codes, all in Montgomery County. Pick one below for details, or look up the full nine-digit ZIP+4 for a specific street address.
All 4 Rockville ZIP codes
| ZIP | Type | County | Population |
|---|---|---|---|
| 20850 | standard | Montgomery | 50,353 |
| 20851 | standard | Montgomery | 14,946 |
| 20852 | standard | Montgomery | 48,180 |
| 20853 | standard | Montgomery | 31,851 |
Finding a ZIP+4 in Rockville
Knowing which of these 4 ZIP codes covers an address only gets you partway. The four-digit extension identifies the specific delivery point — typically one side of one block. Two houses facing each other on the same Rockville street almost always have different ZIP+4 codes even though they share all five leading digits.
Appending ZIP+4 to a mailing list?
Upload a CSV of Rockville addresses and download it complete.