48 zips
| Zip Code | City | Population ↓ |
|---|---|---|
| 20906 | Silver Spring | 71,560 |
| 20878 | Gaithersburg | 65,954 |
| 20874 | Germantown | 61,922 |
| 20904 | Silver Spring | 56,532 |
| 20902 | Silver Spring | 53,308 |
| 20850 | Rockville | 51,072 |
| 20854 | Potomac | 49,320 |
| 20852 | Rockville | 48,379 |
| 20910 | Silver Spring | 45,072 |
| 20877 | Gaithersburg | 38,524 |
| 20817 | Bethesda | 37,795 |
| 20901 | Silver Spring | 37,207 |
| 20886 | Montgomery Village | 34,692 |
| 20853 | Rockville | 31,794 |
| 20815 | Chevy Chase | 31,080 |
| 20814 | Bethesda | 30,234 |
| 20879 | Gaithersburg | 27,489 |
| 20871 | Clarksburg | 27,420 |
| 20876 | Germantown | 26,572 |
| 20912 | Takoma Park | 25,823 |
| 20832 | Olney | 25,488 |
| 20903 | Silver Spring | 25,324 |
| 20895 | Kensington | 19,273 |
| 20905 | Silver Spring | 17,451 |
| 20816 | Bethesda | 17,390 |
| 20866 | Burtonsville | 16,680 |
| 20855 | Derwood | 16,558 |
| 20851 | Rockville | 14,659 |
| 20882 | Gaithersburg | 13,962 |
| 20872 | Damascus | 12,932 |
| 20841 | Boyds | 9,312 |
| 20833 | Brookeville | 7,949 |
| 20837 | Poolesville | 6,651 |
| 20861 | Ashton | 3,031 |
| 20860 | Sandy Spring | 2,279 |
| 20842 | Dickerson | 1,927 |
| 20818 | Cabin John | 1,787 |
| 20896 | Garrett Park | 840 |
| 20868 | Spencerville | 630 |
| 20880 | Washington Grove | 604 |
| 20838 | Barnesville | 368 |
| 20812 | Glen Echo | 282 |
| 20862 | Brinklow | 268 |
| 20839 | Beallsville | 161 |
| 20889 | Bethesda | 158 |
| 20899 | Gaithersburg | 143 |
| 20892 | Bethesda | 0 |
| 20894 | Bethesda | 0 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 48 ZCTAs in Montgomery County, Maryland (US Census).