| Carbon Containment LabNew Haven | Form 990 | $6,164,854FY2024 |
| Society of Plastics Engineers IncDanbury | Form 990 | $4,799,789FY2024 |
| The John B Pierce Laboratory IncNew Haven | Form 990 | $4,647,201FY2024 |
| The Global Foundation for Ocean Exploration IncOld Lyme | Form 990 | $2,422,237FY2025 |
| Talcott Mountain Science Center for Student Involvement IncAvon | Form 990 | $2,010,319FY2025 |
| Inter District Committee for Project OceanologyGroton | Form 990 | $1,496,245FY2025 |
| International Society for Clinical Densitometry IncMiddletown | Form 990 | $1,471,605FY2025 |
| Climatehaven IncNew Haven | Form 990 | $1,191,446FY2024 |
| Connecticut Invention Convention IncHartford | Form 990 | $988,131FY2025 |
| Human Potential Lab IncNew Preston | Form 990 | $747,585FY2024 |
| Association of Symbolic LogicStorrs | Form 990 | $656,892FY2025 |
| Ahepa 110-III IncNorwich | Form 990 | $634,358FY2025 |
| Connecticut Academy of Science and Engineering IncorporatedEast Hartford | Form 990 | $377,317FY2025 |
| Bioethics International IncWestport | Form 990 | $270,186FY2024 |
| Humanity Plus IncGlastonbury | Form 990 | $263,171FY2025 |
| Heffter Research InstituteGreenwich | Form 990 | $228,716FY2024 |
| New England Statistical SocietyStorrs Mansfield | Form 990-EZ | $185,473FY2024 |
| Remote Ecologist IncDarien | Form 990-EZ | $149,536FY2024 |
| Robotics and Beyond IncNew Milford | Form 990-EZ | $109,652FY2024 |
| SB3C Foundation IncFairfield | Form 990-EZ | $109,641FY2025 |
| Salivadirect IncNew Haven | Form 990-EZ | $103,863FY2025 |
| Hopper Belmont Foundation IncCos Cob | Form 990-EZ | $96,333FY2025 |
| Beljanski Foundation IncGreenwich | Form 990 | $94,093FY2024 |
| Technical Investigations Unit of Southwest Connecticut IncEaston | Form 990-EZ | $55,000FY2026 |
| Axion Research Foundation IncHamden | Form 990 | $15,483FY2024 |
| New England Ned Alumni Association IncMiddletown | Form 990-N | No figure |
| Geological Society of ConnecticutHadlyme | Form 990-N | No figure |
| Society of Plastics EngineersDanbury | Form 990-N | No figure |
| Global Institute on Eco-Environment for Sustainable Dev-Giesd IncNew Haven | Form 990-N | No figure |
| Ibm Personal Computer Club of ConnecticutNorwalk | Form 990-N | No figure |
| Technology for Connecticut IncMystic | Form 990-N | No figure |
| Connecticut Professional Genealogists Council IncHartford | Form 990-N | No figure |
| Ocean Technology Foundation IncMystic | Form 990-N | No figure |
| New York New Jersey Flow Cytometry Users Group IncEast Lyme | Form 990-N | No figure |
| Council for Elementary Science InternationalTolland | Form 990-N | No figure |
| Chinese Association for Science and Technology in Connecticut IncStratford | Form 990-N | No figure |
| Connecticut Science OlympiadTolland | Form 990-N | No figure |
| U S Submarine Veterans Technology IncGroton | Form 990-N | No figure |
| International Yan Xin Qigong AssociationMarlborough | Form 990-N | No figure |
| Ai Innovation for Social Impact IncMeriden | Form 990-N | No figure |
| Boothe Memorial Astronomical Society IncShelton | Form 990-N | No figure |
| Astronomical Society of GreenwichCos Cob | Form 990-N | No figure |
| Multiple Comparison Procedures Society IncRidgefield | Form 990-N | No figure |
| Tilde CafeBranford | Form 990-N | No figure |
| Timmers Way IncWilton | Form 990-N | No figure |
| Southern CT ISC2 ChapterNorthford | Form 990-N | No figure |
| Society of Plastics EngineersDanbury | Form 990-N | No figure |
| Small World Initiative IncOld Greenwich | Form 990-N | No figure |
| Semia STEM Outreach CorporationRidgefield | Form 990-N | No figure |
| Litchfield Hills Amateur Astronomy Club IncOxford | Form 990-N | No figure |