| Zip Code | City | Population ↓ |
|---|---|---|
| 12180 | Troy | 53,807 |
| 12144 | Rensselaer | 21,808 |
| 12182 | Troy | 14,790 |
| 12061 | East Greenbush | 10,179 |
| 12033 | Castleton On Hudson | 7,640 |
| 12018 | Averill Park | 7,300 |
| 12198 | Wynantskill | 7,150 |
| 12090 | Hoosick Falls | 5,782 |
| 12123 | Nassau | 4,938 |
| 12196 | West Sand Lake | 3,954 |
| 12138 | Petersburg | 2,922 |
| 12154 | Schaghticoke | 2,820 |
| 12094 | Johnsonville | 2,676 |
| 12121 | Melrose | 2,358 |
| 12052 | Cropseyville | 1,974 |
| 12185 | Valley Falls | 1,785 |
| 12168 | Stephentown | 1,749 |
| 12062 | East Nassau | 1,662 |
| 12140 | Poestenkill | 1,412 |
| 12022 | Berlin | 1,038 |
| 12156 | Schodack Landing | 831 |
| 12153 | Sand Lake | 703 |
| 12063 | East Schodack | 609 |
| 12169 | Stephentown | 379 |
| 12040 | Cherry Plain | 28 |
| 12082 | Grafton | 2 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 26 ZCTAs in Rensselaer County, New York (US Census).