Postal reference / United States
21139Riderwood, Maryland
ZIP code 21139 is a United States postal code for Riderwood, Maryland. Its county association is Baltimore County. The map reference point is at 39.4093, -76.6486.
- State / territory
- Maryland
- Recorded place name
- Riderwood
- County association
- Baltimore
- Estimated coordinate
- 39.4093, -76.6486
View on OpenStreetMap - ZIP prefix
- 211 · 34 ZIP codes share it
- Data source
- GeoNames postal reference, snapshot September 26, 2026
GeoNames reference data. County associations may not include every intersecting county, place names are postal names rather than legal boundaries, and coordinates are approximate. This is not address validation.
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Maryland directoryNearby ZIP code reference points
| ZIP code | Place | State | County association | Miles |
|---|---|---|---|---|
| 21022 | Brooklandville | MD | Baltimore | 1.5 |
| 21093 | Lutherville Timonium | MD | Baltimore | 1.7 |
| 21204 | Towson | MD | Baltimore | 2.4 |
| 21252 | Towson | MD | Baltimore | 2.6 |
| 21284 | Towson | MD | Baltimore | 2.6 |
| 21285 | Towson | MD | Baltimore | 2.6 |
| 21209 | Baltimore | MD | Baltimore (city) | 2.9 |
| 21153 | Stevenson | MD | Baltimore | 3.4 |
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