| # | County | State | Population | Change since 2020 | Unemployment rate |
|---|
| 1 | Iberia Parish | Louisiana | 67,540 | -3.9 % | 4.5 % |
| 2 | Iberville Parish | Louisiana | 29,766 | -1.6 % | 5.0 % |
| 3 | Ida County | Iowa | 6,810 | -2.9 % | 3.0 % |
| 4 | Idaho County | Idaho | 17,912 | 8.3 % | 5.0 % |
| 5 | Imperial County | California | 181,724 | 1.1 % | 18.9 % |
| 6 | Independence County | Arkansas | 38,345 | 1.1 % | 3.7 % |
| 7 | Indian River County | Florida | 172,139 | 7.7 % | 4.7 % |
| 8 | Indiana County | Pennsylvania | 82,953 | -0.3 % | 4.9 % |
| 9 | Ingham County | Michigan | 290,427 | 1.8 % | 5.0 % |
| 10 | Inyo County | California | 18,485 | -2.8 % | 4.6 % |
| 11 | Ionia County | Michigan | 66,250 | -0.8 % | 4.8 % |
| 12 | Iosco County | Michigan | 25,361 | 0.5 % | 8.2 % |
| 13 | Iowa County | Wisconsin | 23,963 | 1.0 % | 2.8 % |
| 14 | Iowa County | Iowa | 16,423 | -1.4 % | 3.8 % |
| 15 | Iredell County | North Carolina | 206,361 | 10.5 % | 3.6 % |
| 16 | Irion County | Texas | 1,526 | 0.8 % | 3.3 % |
| 17 | Iron County | Utah | 65,936 | 15.1 % | 3.2 % |
| 18 | Iron County | Michigan | 11,709 | 0.8 % | 8.1 % |
| 19 | Iron County | Missouri | 9,420 | -1.2 % | 5.2 % |
| 20 | Iron County | Wisconsin | 6,235 | 1.7 % | 5.5 % |
| 21 | Iroquois County | Illinois | 26,067 | -3.7 % | 4.9 % |
| 22 | Irwin County | Georgia | 9,155 | -5.3 % | 3.5 % |
| 23 | Isabella County | Michigan | 65,072 | 1.0 % | 5.6 % |
| 24 | Isanti County | Minnesota | 43,687 | 6.2 % | 5.1 % |
| 25 | Island County | Washington | 86,478 | -0.4 % | 4.6 % |
| 26 | Isle of Wight County | Virginia | 40,942 | 6.0 % | 3.3 % |
| 27 | Issaquena County | Mississippi | 1,295 | -3.0 % | 9.3 % |
| 28 | Itasca County | Minnesota | 45,442 | 0.9 % | 6.2 % |
| 29 | Itawamba County | Mississippi | 24,198 | 1.4 % | 3.4 % |
| 30 | Izard County | Arkansas | 14,291 | 5.2 % | 6.2 % |