| Name | Deductibility Code |
| Brainerd Memorial Library Association Inc. | -- |
| Haddam Cooperative Nursery Association Inc. | -- |
| Haddam Historical Society | -- |
| Haddam Land Trust Inc. | -- |
| Haddam Public Health Inc. | -- |
| Middlesex County Extension Council Incorporated | -- |
| Middletown Festival Road Race Inc. | -- |