| Experimental Aircraft Association IncOshkosh | Form 990 | $53,861,538FY2025 |
| Education Analytics IncMadison | Form 990 | $29,047,057FY2024 |
| WiscnetMadison | Form 990 | $10,562,254FY2025 |
| International Conference on Learning RepresentationsAppleton | Form 990 | $5,082,275FY2024 |
| Applied Superconductivity Educational ConferenceEau Claire | Form 990 | $1,934,079FY2024 |
| Fox-Wolf Watershed Alliance IncAppleton | Form 990 | $1,778,343FY2025 |
| The Water Council IncMilwaukee | Form 990 | $1,686,757FY2025 |
| Forward Biolabs IncMadison | Form 990 | $889,457FY2025 |
| Wisconsin Cranberry Research and Education Foundation IncWisconsin Rapids | Form 990 | $821,530FY2025 |
| Wisconsin Livestock Identification Consortium IncMadison | Form 990 | $512,982FY2025 |
| Makerspace of Milwaukee IncMilwaukee | Form 990 | $496,405FY2025 |
| Society for Affective Science IncMonona | Form 990 | $371,289FY2025 |
| National Motorist Association IncWaunakee | Form 990 | $358,873FY2024 |
| American Filtration and Seperations Society IncMiddleton | Form 990 | $350,610FY2025 |
| Society for Freshwater ScienceAshland | Form 990 | $341,051FY2024 |
| American Association of Veterinary ParasitologistsWindsor | Form 990 | $267,026FY2024 |
| Wisconsin Society for Ornithology IncGrafton | Form 990 | $183,545FY2024 |
| Society of Plastics EngineersSheboygan | Form 990-EZ | $148,147FY2025 |
| Burke Center for Ecosystem Research IncAshland | Form 990-EZ | $135,000FY2024 |
| Wisconsin Society of Science TeachersGreen Bay | Form 990-EZ | $122,464FY2025 |
| Wisconsin Turfgrass Association IncorporatedVerona | Form 990-EZ | $100,621FY2024 |
| Metasub IncMount Pleasant | Form 990-EZ | $90,542FY2024 |
| American Junior Investigator AssociationJanesville | Form 990-EZ | $89,901FY2025 |
| Passenger Vessel Foundation IncStoddard | Form 990 | $75,751FY2024 |
| Friends of Wisconsin Shipwreck Coast National Marine SanctuarySheboygan | Form 990-EZ | $69,947FY2025 |
| Society for Conservation Biology North America IncMilwaukee | Form 990-EZ | $63,827FY2025 |
| Naturist Education Foundation IncOshkosh | Form 990 | $58,059FY2024 |
| Tool Die & Machining Association of Wisconsin Forward Foundation IncGermantown | Form 990-N | No figure |
| 5 Lakes Institute IncMilwaukee | Form 990-N | No figure |
| World Society for Stereotactic and Functional NeurosurgeryFrederic | Form 990-N | No figure |
| DC608 Madison IncMadison | Form 990-N | No figure |
| Chems Users GroupMontello | Form 990-N | No figure |
| Whitewater University Technology Park IncorporatedWhitewater | Form 990-N | No figure |
| Midwest Scientific Glass SocietyGermantown | Form 990-N | No figure |
| Planetpatch IncMadison | Form 990-N | No figure |
| International Sidereal Astrology AssociationGreen Bay | Form 990-N | No figure |
| The Basenji Health EndowmentPoynette | Form 990-N | No figure |
| International Coregonid Symposium 2017 LimitedWashburn | Form 990-N | No figure |
| Creation Science Society of Milwaukee IncMenomonee Falls | Form 990-N | No figure |
| Experimental Aircraft Association Inc Corben Chapter 93Sauk City | Form 990-N | No figure |
| Cedar Grove Ornithological Research Station IncGlenbeulah | Form 990-N | No figure |
| Wisconsin Underwater Archaeological Association IncMount Pleasant | Form 990-N | No figure |
| Tomah Area School District Foundation IncTomah | Form 990-N | No figure |
| Madison Gem and Mineral ClubMadison | Form 990-N | No figure |
| Baraboo Hills Ecology Research Collective IncNorth Freedom | Form 990-N | No figure |
| Racine Astronomical Society IncUnion Grove | Form 990-N | No figure |
| Chippewa Valley Astronomical Society LimitedEau Claire | Form 990-N | No figure |
| Save the Hills Alliance IncMenomonie | Form 990-N | No figure |
| Paranormal Investigators of Milwaukee IncNew Berlin | Form 990-N | No figure |
| 3RINGRiver Falls | Form 990-N | No figure |