11 zips
| Zip Code | City | Population ↓ |
|---|---|---|
| 17837 | Lewisburg | 18,670 |
| 17844 | Mifflinburg | 10,227 |
| 17856 | New Columbia | 3,107 |
| 17845 | Millmont | 2,051 |
| 17887 | White Deer | 810 |
| 17855 | New Berlin | 793 |
| 17886 | West Milton | 657 |
| 17829 | Hartleton | 244 |
| 17885 | Weikert | 221 |
| 17835 | Laurelton | 162 |
| 17880 | Swengel | 46 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 11 ZCTAs in Union County, Pennsylvania (US Census).