Gaithersburg, Maryland ZIP Codes
- ZIP records
5 - Sum of listed ZIP population estimates
143,733 - Counties represented
1 - Population range
57–66,115 per ZIP
Population sum includes positive estimates in these ZIP records; it is not an official city population.
Top ZIP Codes by Population
| Rank | ZIP Code | City | County | Population estimate |
|---|---|---|---|---|
| 1 | 20878 | Gaithersburg | Montgomery | 66,115 |
| 2 | 20877 | Gaithersburg | Montgomery | 38,546 |
| 3 | 20879 | Gaithersburg | Montgomery | 25,264 |
| 4 | 20882 | Gaithersburg | Montgomery | 13,751 |
| 5 | 20899 | Gaithersburg | Montgomery | 57 |
Counties represented
All ZIP Codes in Gaithersburg
- ZIP 20877 — Montgomery County
- ZIP 20878 — Montgomery County
- ZIP 20879 — Montgomery County
- ZIP 20882 — Montgomery County
- ZIP 20899 — Montgomery County
Browse all ZIP data for Maryland
Methodology: ZIP records are grouped by the source file's primary city and state fields. Population ranges and sums use positive ZIP-level estimates; sums should not be read as official city totals. County links use each record's listed county assignment.