Zip Code 20899 — Gaithersburg, MD
20899 is a ZIP Code associated with Gaithersburg, MD, located within Montgomery. 20899 ranks #46 out of 48 ZIP codes in Montgomery County by population (and #457 out of 477 in MD). The area supports an estimated population of 57 residents across Data Pending housing units, with a population density of 207.6 people per square mile.
WorldPlaceData database updated: October 2026
📍 View location on OpenStreetMap (39.144420, -77.216210)
| Data Metric | Local Statistic |
|---|
| Postal / Zip Code | 20899 |
| Primary City | Gaithersburg |
| State / Province | MD |
| County | Montgomery |
| Total Population | 57 |
| Median Household Income | Data Pending |
| Total Housing Units | Data Pending |
| Population Density | 207.6 people/sq mi |
| Timezone | America/New_York |
How 20899 Compares
| Metric | ZIP 20899 | Montgomery County | MD State Average |
|---|
| Population | 57 | 1,076,754 (Total) | 6,205,597 (Total) |
| Average ZIP Income | Data Pending | N/A | N/A |
| Population Density | 207.6 /sq mi | -- | -- |
| County Pop Rank | #46 of 48 | -- | -- |
Nearby ZIP Codes
| ZIP Code | City | Distance | Population | Median Income |
|---|
| Zip 20877 | Gaithersburg | 1.5 mi | 38,546 | N/A |
| Zip 20880 | Washington Grove | 2.2 mi | 577 | N/A |
| Zip 20886 | Montgomery Village | 2.6 mi | 34,718 | N/A |
| Zip 20878 | Gaithersburg | 2.7 mi | 66,115 | N/A |
| Zip 20879 | Gaithersburg | 2.9 mi | 25,264 | N/A |
Data Sources & Methodology: Geographic coordinates and ZIP Code assignments are derived from underlying geographic and postal datasets. Note that ZIP Codes are USPS postal delivery areas, while Census ZCTAs are statistical approximation areas. Read full methodology →