| ZIP Code | ZIP Code City/Town | ZIP Type | Average Adjusted Income(2021) |
|---|
| Caledonia | Standard | $482,610 |
| Cherry Valley | Standard | $353,270 |
| Davis | Standard | $343,600 |
| Davis Junction | Standard | $253,050 |
| Durand | Standard | $332,720 |
| Leaf River | Standard | $314,270 |
| Pecatonica | Standard | $387,130 |
| Rockton | Standard | $470,300 |
| Roscoe | Standard | $406,890 |
| South Beloit | Standard | $435,510 |
| Stillman Valley | Standard | $327,890 |
| Winnebago | Standard | $349,760 |
| Rockford | Standard | $342,040 |
| Rockford | Standard | $315,120 |
| Rockford | Standard | $436,750 |
| Rockford | Standard | $159,990 |
| Rockford | Standard | $445,190 |
| Rockford | Standard | $347,470 |
| Rockford | Standard | $468,360 |
| Loves Park | Standard | $363,690 |
| Rockford | Standard | $584,760 |
| Machesney Park | Standard | $293,880 |
Source: US Internal Revenue Service