| ZIP Code | ZIP Code City/Town | ZIP Type | Average Adjusted Income(2021) |
|---|
| Ransom | Standard | $163,030 |
| Earlville | Standard | $373,920 |
| Leland | Standard | $234,380 |
| Newark | Standard | $465,370 |
| Sandwich | Standard | $348,030 |
| Serena | Standard | $171,360 |
| Sheridan | Standard | $351,450 |
| Somonauk | Standard | $416,650 |
| La Salle | Standard | $459,750 |
| Dana | Standard | $110,570 |
| Grand Ridge | Standard | $323,150 |
| Lostant | Standard | $157,890 |
| Marseilles | Standard | $328,630 |
| Mendota | Standard | $430,500 |
| Oglesby | Standard | $309,910 |
| Ottawa | Standard | $366,930 |
| Peru | Standard | $440,650 |
| Rutland | Standard | $142,930 |
| Seneca | Standard | $327,870 |
| Streator | Standard | $421,660 |
| Tonica | Standard | $394,200 |
| Utica | Standard | $349,330 |
| Wenona | Standard | $387,400 |
Source: US Internal Revenue Service