| Maryland-DC Composting CouncilCockeysville | Form 990-N | No figure |
| 4P Perryman Peninsula Preservation Project IncAberdeen | Form 990-N | No figure |
| Washington Global Charity Foundation IncBeltsville | Form 990-N | No figure |
| Green Spark IncLaurel | Form 990-N | No figure |
| Lead Manage Conserve IncChevy Chase | Form 990-N | No figure |
| Cheverly Green Infrastructure Committee IncCheverly | Form 990-N | No figure |
| Friends of Liberty ReservoirFinksburg | Form 990-N | No figure |
| Mindful MarylandBowie | Form 990-N | No figure |
| Friends of the Ecosystem Restoration Movement IncSilver Spring | Form 990-N | No figure |
| Goode Earth FoundationCapitol Heights | Form 990-N | No figure |
| Restore the Climate IncRockville | Form 990-N | No figure |
| Revive Saree CorpBoyds | Form 990-N | No figure |
| Alliance for Maryland Conservation IncUpper Marlboro | Form 990-N | No figure |
| Kent Island Community GardenChester | Form 990-N | No figure |
| North County Preservation IncorporatedKingsville | None required | No figure |
| Greentrust Alliance IncCockeysville | Form 990 | No figure |
| Solar Consumer Protection Coalition IncColumbia | Form 990-N | No figure |
| Salvaged WorldsHagerstown | Form 990-N | No figure |
| Friends of Antietam Creek and Trovinger MillHagerstown | Form 990-N | No figure |
| Energize MidatlanticShady Side | Form 990-N | No figure |
| HBC Dream FoundationBaltimore | Form 990-N | No figure |
| Patuxent Rediscovered CorporationBenedict | Form 990-N | No figure |
| Akwatribe FoundationTemple Hills | Form 990-N | No figure |
| Community Garden of Hampstead at CrossroadsHampstead | Form 990-N | No figure |
| Interest Custodian Community Cleaning IncBaltimore | Form 990 or 990-EZ | No figure |
| James Edward DarbyChase | Form 990-N | No figure |
| Partners for Nature IncChevy Chase | Form 990 or 990-EZ | No figure |
| Institute for Preservation and Progress IncParkton | Form 990 or 990-EZ | No figure |
| Triple Hands CorporationBaltimore | Form 990-N | No figure |
| Literally Clean CorpClinton | Form 990-N | No figure |
| Greenhood CorporationCollege Park | Form 990-N | No figure |
| Ecoret FoundationBeltsville | Form 990-N | No figure |
| Chesapeake Cactus and Succulent SocietyColumbia | Form 990-N | No figure |
| Peoples Environmental Action and Resilience Learning IncBaltimore | Form 990-N | No figure |
| Sacred Forest Conservancy IncBaltimore | Form 990-N | No figure |
| Eastern Shore Prescribed Burn Association IncSnow Hill | Form 990-N | No figure |
| Our Children FutureOxon Hill | Form 990-N | No figure |
| Seaquality Foundation IncMontgomery Village | Form 990-N | No figure |
| Fishtagged IncGermantown | Form 990-N | No figure |
| National Pollinator Health AllianceUniversity Park | Form 990-N | No figure |
| Wild Link IncRandallstown | Form 990-N | No figure |
| Soulusa BaylifeBerwyn Heights | Form 990-N | No figure |
| The Billy Red Wing Tayac Indigenous Conservation FoundationPort Tobacco | Form 990-N | No figure |
| Chesapeake Future Waters Initiative IncorporatedBel Air | Form 990-N | No figure |
| Bcce Port Towns CollaborativeHyattsville | Form 990 or 990-EZ | No figure |
| Bens Bright Earth and Community FoundationCheverly | Form 990-N | No figure |
| The Green Transition ShowFrederick | Form 990-N | No figure |
| Yellow Metal Bees CorporationAnnapolis | Form 990-N | No figure |
| Leaflearn Environmental Education Institute CorporationPotomac | Form 990-N | No figure |
| Resilient Power Research Foundation LimitedBaltimore | Form 990-N | No figure |