| Name | Deductibility Code |
| Army Air Force Research Association | -- |
| Bessie Spaur Butterfly Garden Inc. | -- |
| Birthright of Knoxville | -- |
| Christs Church of Knoxville Iowa | -- |
| Esther H Browne Scholarship Trust | -- |
| Fire-Rescue Association of Knoxville Iowa | -- |
| Friends of Elk Park | -- |
| Grand Chapter of Iowa Oes | 1,2,6 |
| Helping Hands Food Pantry | -- |
| Knoxville Alumni Association | -- |
| Knoxville Are Community Hospital Foundation | -- |
| Knoxville Community Hospital Inc. | -- |
| Knoxville Education Foundation Inc. | -- |
| Knoxville Heritage Foundation | -- |
| Knoxville Music Boosters Inc. | -- |
| Knoxville Racing Charitable Organization Inc. | -- |
| Knoxville Township Fire Rescue Association | -- |
| Knoxville Volunteer Reserve Police Department | -- |
| Knoxville Youth Initiative Inc. | 4 |
| Livingword Fellowship | -- |
| Marion County Genealogical Society | -- |
| Marion County Historical Society | -- |
| Marion County Humane Society | -- |
| National Alliance for the Mentally Ill Marion County Iowa | -- |
| National Sprint Car Hall of Fame & Museum Foundation Inc. | -- |
| Omega Life Christian Ministries | -- |
| Recruitment of Others for Christs Kingdom Inc. | -- |
| Red Rock Arts Alliance | -- |
| Red Rock Environmental Education Fund | -- |
| Robert Lloyd Crozier and Myrtle Madge Crozier Educational Trust | 4 |
| Stepping Stones Early Learning Center Inc. | -- |
| Turning Point Alternatives to Domestic and Sexual Violence | -- |
| United Way of Knoxville | -- |