48 ZIP Codes
| Zip Code | City | Population ↓ |
|---|---|---|
| 20906 | Silver Spring | 70,595 |
| 20878 | Gaithersburg | 66,115 |
| 20874 | Germantown | 62,738 |
| 20904 | Silver Spring | 58,646 |
| 20902 | Silver Spring | 54,261 |
| 20854 | Potomac | 50,498 |
| 20850 | Rockville | 50,353 |
| 20852 | Rockville | 48,180 |
| 20910 | Silver Spring | 45,943 |
| 20877 | Gaithersburg | 38,546 |
| 20817 | Bethesda | 37,454 |
| 20901 | Silver Spring | 36,435 |
| 20886 | Montgomery Village | 34,718 |
| 20814 | Bethesda | 32,795 |
| 20853 | Rockville | 31,851 |
| 20815 | Chevy Chase | 30,505 |
| 20871 | Clarksburg | 30,182 |
| 20876 | Germantown | 26,406 |
| 20912 | Takoma Park | 25,749 |
| 20832 | Olney | 25,553 |
| 20879 | Gaithersburg | 25,264 |
| 20903 | Silver Spring | 24,815 |
| 20895 | Kensington | 19,184 |
| 20905 | Silver Spring | 19,004 |
| 20816 | Bethesda | 18,140 |
| 20855 | Derwood | 17,279 |
| 20866 | Burtonsville | 15,986 |
| 20851 | Rockville | 14,946 |
| 20872 | Damascus | 13,983 |
| 20882 | Gaithersburg | 13,751 |
| 20841 | Boyds | 9,969 |
| 20833 | Brookeville | 7,860 |
| 20837 | Poolesville | 6,699 |
| 20861 | Ashton | 2,890 |
| 20842 | Dickerson | 2,369 |
| 20860 | Sandy Spring | 2,035 |
| 20818 | Cabin John | 1,539 |
| 20896 | Garrett Park | 932 |
| 20889 | Bethesda | 584 |
| 20880 | Washington Grove | 577 |
| 20862 | Brinklow | 430 |
| 20838 | Barnesville | 306 |
| 20812 | Glen Echo | 276 |
| 20868 | Spencerville | 198 |
| 20839 | Beallsville | 158 |
| 20899 | Gaithersburg | 57 |
| 20894 | Bethesda | 0 |
| 20892 | Bethesda | 0 |
The data shown reflect ZCTAs from the US Census. As of 2025, there are 48 ZCTAs in Montgomery County, Maryland (US Census).