Data / Nonprofits / Maryland / Environment
Environment nonprofits in Maryland: 544 registered with the IRS
544 environment nonprofits are registered with the IRS in Maryland, 533 of them 501(c)(3) charities; the 195 that report revenue took in $399.4 million. The most are in Baltimore (52), Annapolis (30), Bethesda (24). The largest by revenue: Climate United Fund ($48.9 million), National Marine Sanctuary Foundation ($36 million), Chesapeake Bay Foundation Inc ($35.4 million).
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The 500 largest by revenue
| Organization | City | Type | Since | Revenue | Assets | Filing |
|---|---|---|---|---|---|---|
| Climate United Fund | Bethesda | 501(c)(3) | 2023 | $48.9 million | $7.02 billion | 2025-06 |
| National Marine Sanctuary Foundation | Silver Spring | 501(c)(3) | 2001 | $36 million | $15.5 million | 2024-12 |
| Chesapeake Bay Foundation Inc | Annapolis | 501(c)(3) | 1966 | $35.4 million | $127.9 million | 2025-06 |
| Montgomery County Green Bank Corp | Rockville | 501(c)(3) | 2017 | $25.5 million | $141.1 million | 2025-06 |
| Alliance for the Chesapeake Bay Inc | Annapolis | 501(c)(3) | 1978 | $16 million | $10.6 million | 2024-12 |
| Chesapeake Conservancy Inc | Annapolis | 501(c)(3) | 2008 | $14 million | $20.6 million | 2025-09 |
| Oceantic Network Inc | Baltimore | 501(c)(3) | 2015 | $11.9 million | $11.6 million | 2024-12 |
| Shorerivers Inc | Easton | 501(c)(3) | 2008 | $11.3 million | $4.8 million | 2025-12 |
| Trees for the Future Inc | Silver Spring | 501(c)(3) | 1989 | $9.9 million | $5.4 million | 2025-12 |
| Environmental Policy Innovation Center | College Park | 501(c)(3) | 2023 | $7.9 million | $4 million | 2025-12 |
| Southern Maryland Resource Conservation & Development Board | Leonardtown | 501(c)(3) | 1981 | $7.4 million | $3.3 million | 2025-06 |
| Wild Earth Allies Inc | Chevy Chase | 501(c)(3) | 1981 | $7 million | $11.3 million | 2025-12 |
| Nature Forward Inc | Chevy Chase | 501(c)(3) | 1947 | $5.9 million | $15.9 million | 2025-08 |
| Western Maryland Resource Conservation and Development | Hagerstown | 501(c)(3) | 1994 | $5.9 million | $963,227 | 2025-06 |
| Baltimore Tree Trust Inc | Baltimore | 501(c)(3) | 2009 | $5.8 million | $3.3 million | 2024-12 |
| Land Preservation Trust Inc | Cockeysville | 501(c)(3) | 1986 | $5.5 million | $4 million | 2024-12 |
| Solid Waste Association of North America Inc | Silver Spring | 501(c)(3) | 1986 | $5.4 million | $3.4 million | 2025-06 |
| National Park Trust Inc | Rockville | 501(c)(3) | 1991 | $4.7 million | $8.6 million | 2025-06 |
| Maryland Coastal Bays Foundation Inc | Berlin | 501(c)(3) | 1999 | $4.5 million | $1.2 million | 2025-09 |
| Chesapeake Climate Action Network | Takoma Park | 501(c)(3) | 2004 | $4 million | $3.4 million | 2025-06 |
| Izaak Walton League of America Inc | Gaithersburg | 501(c)(3) | 1985 | $4 million | $13.4 million | 2025-12 |
| Irvine Natural Science Center Inc | Owings Mills | 501(c)(3) | 1981 | $3.8 million | $16.4 million | 2025-06 |
| American Lumber Standard Committee Incorporated | Frederick | 501(c)(3) | 2005 | $3.8 million | $6.6 million | 2025-12 |
| Center for Watershed Protection | Fulton | 501(c)(3) | 1993 | $3.8 million | $2.7 million | 2024-12 |
| Moonshot Missions Inc | Bethesda | 501(c)(3) | 2022 | $3.8 million | $1.1 million | 2025-12 |
| Rachel Carson Council Inc | Bethesda | 501(c)(3) | 1967 | $3.6 million | $8.3 million | 2025-12 |
| Blue Water Baltimore | Baltimore | 501(c)(3) | 1994 | $3.6 million | $1.4 million | 2025-12 |
| Arundel Rivers Federation Inc | Edgewater | 501(c)(3) | 2001 | $3.5 million | $2.7 million | 2025-12 |
| Foundations of Success Inc | Bethesda | 501(c)(3) | 2007 | $3.1 million | $2.8 million | 2024-12 |
| Rock Creek Conservancy Inc | Bethesda | 501(c)(3) | 2006 | $2.9 million | $3.2 million | 2025-12 |
| Anacostia Watershed Society Inc | Bladensburg | 501(c)(3) | 1990 | $2.6 million | $2.2 million | 2024-12 |
| National Council On Radiation Protection and Measurements | Bethesda | 501(c)(3) | 1964 | $2.5 million | $2.6 million | 2024-12 |
| Potomac Conservancy Inc | Bethesda | 501(c)(3) | 1993 | $2.5 million | $3.4 million | 2025-09 |
| Howard County Conservancy Inc | Woodstock | 501(c)(3) | 1991 | $2.4 million | $7.5 million | 2024-12 |
| Mid Atlantic Regional Air Management Assocation Inc | Towson | 501(c)(3) | 2006 | $2.3 million | $324,580 | 2025-09 |
| Public Employees for Environmental Responsibility Inc | Silver Spring | 501(c)(3) | 1995 | $2.2 million | $1.2 million | 2025-09 |
| Chesapeake Research Consortium Inc | Edgewater | 501(c)(3) | 1973 | $2.2 million | $699,156 | 2025-06 |
| Marec Action | Silver Spring | 501(c)(4) | 2021 | $2.2 million | $1.6 million | 2025-06 |
| Maryland Forestry Boards Foundation Inc | Annapolis | 501(c)(3) | 1990 | $2.1 million | $194,411 | 2025-12 |
| Alice Ferguson Foundation Inc | Accokeek | 501(c)(3) | 2008 | $2.1 million | $11.2 million | 2025-12 |
| Friends of Patterson Park Inc | Baltimore | 501(c)(3) | 2000 | $2.1 million | $3.4 million | 2024-12 |
| Echo Hill Outdoor School Inc | Worton | 501(c)(3) | 1973 | $2 million | $3.5 million | 2024-12 |
| Upstream Alliance Inc | Annapolis | 501(c)(3) | 2016 | $2 million | $4.5 million | 2025-12 |
| Voices for A Sustainable Future Inc | Takoma Park | 501(c)(3) | 2010 | $2 million | $2.3 million | 2024-12 |
| C&O Canal Trust Inc | Williamsport | 501(c)(3) | 2007 | $1.9 million | $2.3 million | 2025-09 |
| Anne Arundel County Watershed Stewards Academy Inc | Millersville | 501(c)(3) | 2011 | $1.9 million | $1.7 million | 2025-12 |
| Howard Ecoworks Inc | Columbia | 501(c)(3) | 2017 | $1.8 million | $1.6 million | 2025-12 |
| Eastern Shore Land Conservancy Inc | Easton | 501(c)(3) | 1991 | $1.8 million | $19.4 million | 2025-06 |
| Environmental Concern Inc | St Michael | 501(c)(3) | 1973 | $1.8 million | $1.7 million | 2024-11 |
| Majority Action | Silver Spring | 501(c)(3) | 2018 | $1.5 million | $807,078 | 2024-12 |
| Maryland League of Conservation Voters Education Fund | Annapolis | 501(c)(3) | 2000 | $1.5 million | $1.4 million | 2024-12 |
| Chesapeake Legal Alliance Inc | Annapolis | 501(c)(3) | 2009 | $1.5 million | $1.6 million | 2025-06 |
| Chesapeake Audubon Society | Easton | 501(c)(3) | 1975 | $1.5 million | $9.3 million | 2025-06 |
| Severn River Association Inc | Annapolis | 501(c)(3) | 2000 | $1.4 million | $1.7 million | 2025-12 |
| Nuclear Information & Resource Service | Mount Rainier | 501(c)(3) | 1978 | $1.4 million | $909,875 | 2025-01 |
| Team River Runner Inc | Rockville | 501(c)(3) | 2014 | $1.4 million | $1.6 million | 2024-12 |
| Bay Journal Media Inc | Mayo | 501(c)(3) | 2008 | $1.4 million | $656,671 | 2025-06 |
| Cecil Land Trust | Elkton | 501(c)(3) | 1999 | $1.4 million | $1.7 million | 2025-12 |
| Defensores de La Cuenca | Hyattsville | 501(c)(3) | 2020 | $1.3 million | $635,593 | 2024-12 |
| Opportunity Ministries Inc | Pasadena | 501(c)(3) | 2014 | $1.2 million | $3 million | 2025-05 |
| Adkins Arboretum LTD | Ridgely | 501(c)(3) | 1980 | $1.1 million | $5.6 million | 2024-12 |
| Interfaith Partners for the Chesapeake Inc | Annapolis | 501(c)(3) | 2015 | $1.1 million | $674,367 | 2024-12 |
| Cylburn Arboretum Friends Inc | Baltimore | 501(c)(3) | 1971 | $1.1 million | $8.9 million | 2025-12 |
| Ioos Association | Silver Spring | 501(c)(3) | 2013 | $1.1 million | $583,372 | 2025-09 |
| Lower Shore Land Trust Inc | Snow Hill | 501(c)(3) | 1993 | $1 million | $2.6 million | 2025-12 |
| Chesapeake Rivers Association Inc | Annapolis | 501(c)(3) | 2002 | $1 million | $198,856 | 2025-12 |
| American Chestnut Land Trust Inc | PRNC Frederck | 501(c)(3) | 1987 | $981,870 | $8.2 million | 2023-12 |
| American Center for Life Cycle Assessment | Bethesda | 501(c)(6) | 2024 | $936,969 | $328,149 | 2024-12 |
| Vine Corps Inc | Cheverly | 501(c)(3) | 2014 | $844,153 | $735,986 | 2025-06 |
| Baltimore Green Space A Land Trustfor Community-Managed Open Space in | Baltimore | 501(c)(3) | 2008 | $841,361 | $245,938 | 2024-12 |
| Chesapeake Wildlife Heritage Inc | Chester | 501(c)(3) | 1988 | $803,635 | $5.2 million | 2024-12 |
| Our Climate Education Fund | Bethesda | 501(c)(3) | 2008 | $796,801 | $332,470 | 2023-12 |
| Scenic Rivers Land Trust Inc | Annapolis | 501(c)(3) | 1990 | $777,020 | $2.7 million | 2024-12 |
| Old-Growth Forest Network | Berlin | 501(c)(3) | 2013 | $690,347 | $1.2 million | 2024-12 |
| National Turfgrass Evaluation Program Inc | Beltsville | 501(c)(3) | 1993 | $689,564 | $296,523 | 2025-06 |
| Thorpewood | Frederick | 501(c)(3) | 2024 | $668,596 | $62,843 | 2025-12 |
| Evergreen Heritage Center Foundation Inc | Frostburg | 501(c)(3) | 2009 | $625,314 | $966,596 | 2025-12 |
| Ecolatinos Inc | College Park | 501(c)(3) | 2018 | $594,596 | $363,687 | 2024-12 |
| Back River Restoration Committee Inc | Baltimore | 501(c)(3) | 2009 | $591,647 | $201,221 | 2025-12 |
| Harford Land Trust Inc | Bel Air | 501(c)(3) | 1991 | $558,171 | $3.3 million | 2025-12 |
| Solutions From the Land | Luthvle Timon | 501(c)(3) | 2015 | $553,586 | $232,805 | 2025-12 |
| Chesapeake Conservation Landscaping Council Inc | Ridgely | 501(c)(3) | 2009 | $542,975 | $114,137 | 2024-12 |
| Catoctin Land Trust Inc | Frederick | 501(c)(3) | 2002 | $530,672 | $714,402 | 2025-06 |
| Chesapeake Stormwater Network Inc | Catonsville | 501(c)(3) | 2009 | $511,702 | $399,772 | 2025-06 |
| Neighbor Space of Baltimore County | Lutherville | 501(c)(3) | 2004 | $494,713 | $3.6 million | 2025-06 |
| Fair Hill Environmental Foundation Inc | Elkton | 501(c)(3) | 1990 | $491,484 | $321,026 | 2025-12 |
| Solar Freeze Inc | Hyattsville | 501(c)(3) | 2019 | $435,900 | $454,639 | 2024-12 |
| Gunpowder Riverkeeper Inc | Monkton | 501(c)(3) | 2010 | $431,484 | $151,730 | 2024-12 |
| Association for Nature -Based Education Inc | Glen Arm | 501(c)(3) | 2017 | $416,057 | $171,265 | 2025-06 |
| Fox Haven Center | Jefferson | 501(c)(3) | 2004 | $410,766 | $201,308 | 2024-12 |
| Climate Access Fund Corporation | Baltimore | 501(c)(3) | 2019 | $406,076 | $3.9 million | 2025-12 |
| Roland Park Community Foundation Inc | Baltimore | 501(c)(3) | 1987 | $385,955 | $8.3 million | 2024-12 |
| Land and Cultural Preservation Fund Inc | Walkersville | 501(c)(3) | 2007 | $382,433 | $218,300 | 2024-12 |
| Izaak Walton League of America Inc | Damascus | 501(c)(3) | 1985 | $355,188 | $2.2 million | 2024-12 |
| Species Survival Network | Highland | 501(c)(3) | 1999 | $346,428 | $355,664 | 2024-12 |
| Bethesda Green | Bethesda | 501(c)(3) | 2008 | $341,433 | $191,248 | 2024-12 |
| Waterkeepers Chesapeake Inc | Silver Spring | 501(c)(3) | 2015 | $312,302 | $260,733 | 2025-12 |
| Assateague Coastal Trust Inc | Berlin | 501(c)(3) | 1982 | $309,462 | $294,857 | 2025-12 |
| United for Clean Power | Bowie | 501(c)(4) | 2015 | $305,673 | $4,131 | 2024-12 |
| St Marys River Watershed Association Inc | St Marys City | 501(c)(3) | 2006 | $301,440 | $425,647 | 2025-12 |
| One Montgomery Green Inc | Silver Spring | 501(c)(3) | 2015 | $292,551 | $80,850 | 2025-12 |
| Friskys Wildlife & Primate Sanctuary Inc | Woodstock | 501(c)(3) | 1998 | $291,729 | $548,780 | 2024-12 |
| Ocean Research Project Inc | Annapolis | 501(c)(3) | 2012 | $267,950 | $48,186 | 2025-06 |
| Izaak Walton League of America Inc | Germantown | 501(c)(3) | 1985 | $264,764 | $2.3 million | 2025-12 |
| Echoes of Nature Inc | Bowie | 501(c)(3) | 2010 | $258,280 | $149,014 | 2025-12 |
| Horizon of Hope Inc | Woodbine | 501(c)(3) | 2024 | $244,531 | $274,641 | 2025-12 |
| Patuxent Tidewater Land Trust | Leonardtown | 501(c)(3) | 1997 | $222,808 | $1.9 million | 2025-12 |
| Restore the Earth Foundation Inc | Easton | 501(c)(3) | 2010 | $217,709 | $17.4 million | 2024-12 |
| Oceanites Inc | Chevy Chase | 501(c)(3) | 1987 | $217,335 | $82,540 | 2024-12 |
| Earthreports Inc | Uppr Marlboro | 501(c)(3) | 2022 | $209,516 | $82,670 | 2025-09 |
| Charles Koiner Center for Urban Farming | Silver Spring | 501(c)(3) | 2018 | $204,075 | $62,002 | 2024-12 |
| Green Advantage Inc | Frederick | 501(c)(3) | 1997 | $191,218 | $151,578 | 2025-12 |
| Little Falls Watershed Alliance Inc | Chevy Chase | 501(c)(3) | 2009 | $188,070 | $167,868 | 2025-12 |
| ZNRG Foundation Inc | Potomac | 501(c)(3) | 2022 | $187,251 | $166,356 | 2025-12 |
| Baltimore County Land Trust Coalition Inc | Hunt Valley | 501(c)(3) | 2025 | $178,434 | $97,490 | 2025-12 |
| Anchor Point Inc | Cambridge | 501(c)(3) | 2009 | $177,812 | $487,022 | 2025-06 |
| Lower Susquehanna Heritage Greenway Inc | Darlington | 501(c)(3) | 1998 | $174,237 | $217,632 | 2025-06 |
| Kent Narrows Development Foundation | Chester | 501(c)(3) | 2013 | $170,199 | $377,459 | 2025-12 |
| Volunteer Team Inc | Flintstone | 501(c)(3) | 1996 | $168,436 | $155,695 | 2025-12 |
| Talbot County Garden Club Inc | Easton | 501(c)(3) | 2006 | $165,170 | $728,089 | 2024-06 |
| Mobilize Frederick | Frederick | 501(c)(3) | 2023 | $164,317 | $72,555 | 2024-12 |
| Algonquin Ultras Inc | Fruitland | 501(c)(3) | 2017 | $160,852 | $117,045 | 2025-12 |
| Filbert Street Garden | Baltimore | 501(c)(3) | 2020 | $158,421 | $169,148 | 2025-12 |
| Climb for Hope Inc | Baltimore | 501(c)(3) | 2007 | $144,726 | $64,329 | 2024-12 |
| Ocean City Reef Foundation | Berlin | 501(c)(3) | 2000 | $143,608 | $75,504 | 2025-12 |
| Oregon Ridge Nature Center Council | Cockeysville | 501(c)(3) | 1982 | $142,015 | $570,646 | 2025-08 |
| Delmarva RC&D Inc | Cambridge | 501(c)(3) | 2018 | $140,998 | $2,404 | 2025-06 |
| Minorities in Aquaculture | Easton | 501(c)(3) | 2020 | $139,143 | $100,000 | 2023-12 |
| Spa Creek Conservancy | Annapolis | 501(c)(3) | 2004 | $138,211 | $150,721 | 2025-12 |
| Phillips Wharf Environmental Centerinc | Easton | 501(c)(3) | 2007 | $135,850 | $189,092 | 2025-12 |
| Eastern Shore Heritage Inc | Chestertown | 501(c)(3) | 2001 | $135,386 | $215,829 | 2025-06 |
| Maryland Forests Association Inc | Linkwood | 501(c)(3) | 1982 | $132,603 | $212,827 | 2025-12 |
| Forever Maryland Foundation Inc | Easton | 501(c)(3) | 2007 | $132,026 | $112,011 | 2025-06 |
| Gemm Comm Limited | Forestville | 501(c)(3) | 2021 | $129,825 | $48,785 | 2025-12 |
| Friends of Herring Run Parks Inc | Baltimore | 501(c)(3) | 2014 | $124,240 | $121,071 | 2024-12 |
| The Manor Conservancy Inc | Monkton | 501(c)(3) | 1994 | $114,869 | $848,253 | 2024-12 |
| Friends of Calvert State Park Inc | Lusby | 501(c)(3) | 1999 | $114,178 | $187,822 | 2025-12 |
| Friends of Blackwater Incorporated | Cambridge | 501(c)(3) | 1988 | $113,438 | $299,916 | 2025-09 |
| Ecosikh Incorporated | Silver Spring | 501(c)(3) | 2012 | $111,342 | $191,660 | 2024-12 |
| Deep Creek Watershed Foundation Inc | Oakland | 501(c)(3) | 2016 | $110,951 | $297,943 | 2025-12 |
| Smart-On-Smart | Takoma Park | 501(c)(3) | 2020 | $110,250 | $133,381 | 2025-12 |
| Turner Station Conservation Teams Inc | Dundalk | 501(c)(3) | 2015 | $109,277 | $109,857 | 2024-12 |
| Climatecritical Earth | Baltimore | 501(c)(3) | 2022 | $107,400 | $56,956 | 2024-12 |
| Silvoculture Inc | Frederick | 501(c)(3) | 2019 | $106,918 | $54,295 | 2025-12 |
| Center for Ecosystem Recovery Corp | Millersville | 501(c)(3) | 2023 | $104,000 | $2,917 | 2025-06 |
| Association for Environmental Studies and Sciences | Halethorpe | 501(c)(3) | 2011 | $99,854 | $45,035 | 2025-12 |
| Annapolis Green Inc | Annapolis | 501(c)(3) | 2017 | $98,844 | $50,870 | 2024-12 |
| Trash Free Maryland | Baltimore | 501(c)(3) | 2015 | $95,000 | $241,848 | 2024-12 |
| Way the Truth and Light Missionary Foundation | Joppa | 501(c)(3) | 2021 | $94,095 | $9,251 | 2025-12 |
| Magothy River Association Inc | Severna Park | 501(c)(3) | 2007 | $90,708 | $164,724 | 2025-12 |
| Common Ground Earth Inc | Bel Air | 501(c)(3) | 2025 | $85,788 | $49,989 | 2025-12 |
| Wicomico Environmental Trust LTD | Salisbury | 501(c)(3) | 2005 | $80,526 | $128,795 | 2024-12 |
| Calvert Nature Society Inc | Port Republic | 501(c)(3) | 2024 | $77,088 | $1.8 million | 2025-06 |
| Our Zero Waste Future Incorporated | Baltimore | 501(c)(3) | 2022 | $74,295 | $51,303 | 2024-12 |
| Maryland State Game and Fish Protective Association Inc | Perry Hall | 501(c)(3) | 2003 | $73,436 | $73,957 | 2025-12 |
| Friends of Sligo Creek | Takoma Park | 501(c)(3) | 2002 | $71,290 | $148,091 | 2025-12 |
| Center for Ecological Living and Learning | Derwood | 501(c)(3) | 2004 | $69,268 | $239,022 | 2024-12 |
| Elyssa Kellerman Foundation Corporation | Bethesda | 501(c)(3) | 2024 | $67,750 | $33,752 | 2025-12 |
| Catonsville Rails To Trail Inc | Catonsville | 501(c)(3) | 1999 | $65,943 | $25,658 | 2025-12 |
| Inclusive Clean Energy for Those Underserved | Bowie | 501(c)(3) | 2023 | $65,535 | $1,041 | 2025-12 |
| Environmental Engineering FNDT Inc | Annapolis | 501(c)(3) | 2006 | $62,605 | $362,691 | 2025-12 |
| Assateague Island Alliance | Berlin | 501(c)(3) | 2008 | $60,935 | $105,791 | 2025-12 |
| Community Food Forest Collective Inc | Takoma Park | 501(c)(3) | 2024 | $59,327 | $33,758 | 2025-06 |
| The Maryland Recycling Network Inc | Columbia | 501(c)(3) | 1992 | $56,210 | $51,567 | 2025-12 |
| Meade Natural Heritage Association Inc | Severn | 501(c)(3) | 1994 | $52,905 | $21,664 | 2026-06 |
| Green Spring Valley Garden Club Inc | Brooklandvl | 501(c)(3) | 2025 | $52,436 | $146,958 | 2025-12 |
| Maryland City Communities Association Inc | Laurel | 501(c)(3) | 2013 | $50,725 | $93,517 | 2025-12 |
| Upcycled Inc | Columbia | 501(c)(3) | 2020 | $49,761 | $38,960 | 2025-12 |
| Go Green Oc Inc | Ocean City | 501(c)(3) | 2019 | $44,895 | $36,133 | 2025-06 |
| Kent Conservation and Preservation Alliance | Chestertown | 501(c)(3) | 2015 | $40,418 | $34,971 | 2025-12 |
| Summerseat Farm Inc | Mechanicsvlle | 501(c)(3) | 2000 | $39,092 | $462,180 | 2025-12 |
| Calvert Environmental Trust for Youth Inc | PRNC Frederck | 501(c)(3) | 1996 | $37,050 | $571,121 | 2024-12 |
| The Garden Club of the Eastern Shore Inc | Easton | 501(c)(3) | 2021 | $35,194 | $188,977 | 2025-12 |
| Horticulture Society of Maryland Inc | Luthvle Timon | 501(c)(3) | 2000 | $33,452 | $63,265 | 2025-08 |
| Western Garret County State Park Volunteers Inc | Accident | 501(c)(3) | 2006 | $32,662 | $114,386 | 2025-12 |
| Holly Springs Nature Conservancy and Wildlife Sanctuary Inc | Hampstead | 501(c)(3) | 2007 | $28,990 | $1.3 million | 2024-12 |
| Port Tobacco River Conservancy Inc | Port Tobacco | 501(c)(3) | 2005 | $22,298 | $5,123 | 2025-12 |
| Bay Paddle Inc | Arnold | 501(c)(3) | 2020 | $21,784 | $2,546 | 2024-12 |
| Global Smart Grid Federation | Baltimore | 501(c)(3) | 2013 | $20,467 | $1 | 2024-12 |
| Long Green Valley Conservancy Inc | Baldwin | 501(c)(3) | 1996 | $19,800 | $127,712 | 2025-12 |
| Maryland State Geographic Information Committee LTD | Crownsville | 501(c)(3) | 2014 | $17,061 | $17,764 | 2025-12 |
| Minnies Island Community Conservancy Corp | Cabin John | 501(c)(3) | 2021 | $16,486 | $693,423 | 2025-12 |
| Crownsville Conservancy Inc | Crownsville | 501(c)(3) | 2006 | $11,199 | $985,264 | 2025-12 |
| Muddy Branch Alliance Inc | Gaithersburg | 501(c)(3) | 2011 | $9,875 | $40,621 | 2024-12 |
| Chesapeake Heritage Conservancy Inc | Elton | 501(c)(3) | 1995 | $9,317 | $104,034 | 2024-12 |
| Prince Georges Audubon Society Incorporated | Bowie | 501(c)(3) | 2016 | $7,994 | $11,761 | 2025-12 |
| Earth Help Today Inc | Bethesda | 501(c)(3) | 2020 | $6,600 | $3,794 | 2024-12 |
| Concerned Citizens for Proper Land Use Inc | Annapolis | 501(c)(3) | 2021 | $3,889 | $96,656 | 2025-12 |
| Southern Calvert Land Trust Inc | Lusby | 501(c)(3) | 2001 | $3,575 | $15,006 | 2025-06 |
| Lake Linganore Conservation Society Inc | New Market | 501(c)(3) | 1999 | $3,471 | $70,514 | 2024-12 |
| Central Maryland Heritage League Inc | Middletown | 501(c)(3) | 1990 | $261 | $465,581 | 2024-12 |
| Magothy River Land Trust Inc | Severna Park | 501(c)(3) | 1992 | $210 | $3,179 | 2025-12 |
| Mid-Maryland Land Trust Association Inc | Frederick | 501(c)(3) | 2006 | $50 | $20,673 | 2025-12 |
| Clean Islands International Inc | Pasadena | 501(c)(3) | 1993 | $32 | $177,247 | 2022-12 |
| Mid-Atlantic Renewable Energy Coalition | Silver Spring | 501(c)(3) | 2010 | $1 | $23,338 | 2025-06 |
| 350 Montgomery County Inc | Kensington | 501(c)(3) | 2015 | $0 | $0 | 2024-09 |
| 4P Perryman Peninsula Preservation Project Inc | Aberdeen | 501(c)(3) | 2024 | $0 | $0 | 2025-12 |
| Adaptation Leader Inc | Bethesda | 501(c)(3) | 2022 | $0 | $0 | 2025-12 |
| Advocates for Herring Bay | Tracys LNDG | 501(c)(3) | 2025 | $0 | $0 | 2025-12 |
| Africa Environmental Watch & Services Inc | Bowie | 501(c)(3) | 2006 | $0 | $0 | 2024-12 |
| African Islands Business Council | Laurel | 501(c)(3) | 2024 | $0 | $0 | 2025-12 |
| Akwatribe Foundation | Temple Hills | 501(c)(3) | 2025 | |||
| Alliance for Maryland Conservation Inc | Uppr Marlboro | 501(c)(3) | 2024 | $0 | $0 | 2024-12 |
| American Clean Skies Foundation Inc | Chevy Chase | 501(c)(3) | 2007 | $869,940 | 2024-12 | |
| American Language Fund | Ft Washington | 501(c)(3) | 2022 | $0 | $0 | 2023-12 |
| Americans for the Conservation of Barroso Portugal Inc | Annapolis | 501(c)(3) | 2023 | $0 | $0 | 2025-12 |
| Ames Shalom Community Inc | Baltimore | 501(c)(3) | 2000 | $0 | $0 | 2023-12 |
| Amplify the Future Inc | Frederick | 501(c)(3) | 2021 | $0 | $0 | 2025-12 |
| Annapolis Horticultural Society | Annapolis | 501(c)(7) | 2000 | $0 | $0 | 2025-02 |
| Anns Backyard Forest LTD | Bethesda | 501(c)(3) | 2025 | $0 | $0 | 2025-12 |
| Antietam-Conococheague Watershed Alliance Inc | Hagerstown | 501(c)(3) | 2008 | $0 | $0 | 2024-12 |
| Aqua Kids TV Inc | Baltimore | 501(c)(3) | 2016 | $0 | $0 | 2023-12 |
| Araybeam Citizens Energy | Annapolis | 501(c)(3) | 2023 | |||
| Artistree | Frederick | 501(c)(3) | 2019 | $0 | $0 | 2024-04 |
| Asks Inc | Shady Side | 501(c)(3) | 2019 | $0 | $0 | 2025-12 |
| Audubon Society of Central Maryland Inc | Mount Airy | 501(c)(3) | 1986 | $0 | $0 | 2025-06 |
| Baltimore Herb Festival Inc | Gwynn Oak | 501(c)(3) | 1998 | $0 | $0 | 2025-09 |
| Baltimore Reforestation Project Inc | Baltimore | 501(c)(3) | 2021 | $0 | $0 | 2024-12 |
| Bana Kasende Foundation | Frederick | 501(c)(3) | 2022 | $0 | $0 | 2025-12 |
| Bay Hundred Foundation Inc | St Michaels | 501(c)(3) | 2005 | $0 | $0 | 2024-12 |
| Bcce Port Towns Collaborative | Hyattsville | 501(c)(3) | 2026 | |||
| Beach Project | Parkville | 501(c)(3) | 2024 | $289 | 2024-12 | |
| Bear Branch Sanctuary Inc | Bryans RD | 501(c)(3) | 2026 | $0 | $0 | 2025-12 |
| Beaver Creek Watershed Association Inc | Funkstown | 501(c)(3) | 2004 | $0 | $0 | 2025-12 |
| Beltsville Garden Club Inc | Beltsville | 501(c)(3) | 2017 | $0 | $0 | 2025-08 |
| Belvedere Community Association Inc | Arnold | 501(c)(3) | 2021 | $0 | $0 | 2025-12 |
| Bens Bright Earth and Community Fou Ndation | Cheverly | 501(c)(3) | 2026 | |||
| Berkshire-Eastwood Recreation and Parks Council | Baltimore | 501(c)(3) | 2013 | $0 | $0 | 2025-12 |
| Betty Huse M D Charitable Foundation | Baltimore | 501(c)(3) | 2001 | $970,827 | 2025-12 | |
| Beyond Coral Foundation Corp | Rockville | 501(c)(3) | 2019 | $0 | $0 | 2026-06 |
| Black Swamp Creek Land Trust | Brandywine | 501(c)(3) | 2006 | $0 | $0 | 2025-12 |
| Blackwater Conservation Association Inc | Edgewater | 501(c)(3) | 2024 | $0 | $0 | 2025-12 |
| Blue Moon Rising Center for Sustainable Education Inc | McHenry | 501(c)(3) | 2014 | $0 | $0 | 2025-12 |
| Blue Ripple Effect Inc | Potomac | 501(c)(3) | 2024 | |||
| Bowleys Quarters Community Association Incorporated | Middle River | 501(c)(4) | 2010 | $0 | $0 | 2025-12 |
| Braddock Run Watershed Association | Lavale | 501(c)(3) | 2008 | $0 | $0 | 2025-12 |
| Broadwater Creek Coalition Inc | Churchton | 501(c)(3) | 2013 | $0 | $0 | 2025-12 |
| Brook South Fultons Camp Creek Cons Ervation Club Inc | Towson | 501(c)(3) | 2025 | $0 | $0 | 2025-12 |
| Brooklandville Station | Lutherville | 501(c)(3) | 2025 | $0 | $0 | 2025-12 |
| Bucktail Rod & Gun Club of Arnold I NC | Arnold | 501(c)(3) | 2025 | $0 | $0 | 2025-12 |
| Buildingaction | Potomac | 501(c)(4) | 2021 | $0 | $0 | 2024-12 |
| Calico Fields Environmental Education Inc | Millington | 501(c)(3) | 2020 | $0 | $0 | 2025-12 |
| Cape Conservation Corps | Annapolis | 501(c)(3) | 2017 | $0 | $0 | 2025-12 |
| Cape St Claire Garden Club | Annapolis | 501(c)(3) | 2017 | $0 | $0 | 2025-12 |
| Capital Foundation for Energy and A I | Laurel | 501(c)(3) | 2026 | |||
| Carroll County Land Trust Inc | Westminster | 501(c)(3) | 1993 | $0 | $0 | 2025-12 |
| Catoctin Forest Alliance Inc | Thurmont | 501(c)(3) | 2010 | $0 | $0 | 2025-12 |
| Cedar Haven Civic Association On the Patuxent River Inc | Brandywine | 501(c)(3) | 2018 | $0 | $0 | 2023-12 |
| Center for Invasive Species Prevention Inc | Bethesda | 501(c)(3) | 2015 | $0 | $0 | 2025-12 |
| Center for Responsible Technology Inc | Bethesda | 501(c)(3) | 2024 | $0 | $0 | 2025-12 |
| Change 4 Good Incorporated | Ft Washington | 501(c)(3) | 2015 | $0 | $0 | 2025-12 |
| Charm City Park Stewards Inc | Towson | 501(c)(3) | 2026 | |||
| Cherish the Earth-Bal Tashcis Company | Baltimore | 501(c)(3) | 2020 | $0 | $0 | 2024-12 |
| Chesapeake Bay Association Inc | Sparrows PT | 501(c)(3) | 2021 | $0 | $0 | 2025-06 |
| Chesapeake Bay Herb Society Inc | Easton | 501(c)(3) | 2004 | $0 | $0 | 2025-12 |
| Chesapeake Cactus and Succulent Soc Iety | Columbia | 501(c)(3) | 2026 | |||
| Chesapeake Chapter of Awma | Baltimore | 501(c)(3) | 2025 | $0 | $0 | 2025-12 |
| Chesapeake Education Arts and Research Society | Sandy Spring | 501(c)(3) | 2006 | $0 | $0 | 2024-12 |
| Chesapeake Energy Conservation Inc | St Michaels | 501(c)(3) | 2014 | $0 | $0 | 2025-06 |
| Chesapeake Future Waters Initiative Incorporated | Bel Air | 501(c)(3) | 2026 | |||
| Chesapeake Heritage Archeological and Paleontological Foundation Inc | Saint Leonard | 501(c)(3) | 2023 | $0 | $0 | 2025-12 |
| Chesapeake Islands Research Center Inc | Baltimore | 501(c)(3) | 2024 | $867 | 2024-12 | |
| Chesapeake Power Foundation Inc | Bethesda | 501(c)(3) | 2022 | $3.5 million | 2025-12 | |
| Cheverly Green Infrastructure Committee Inc | Cheverly | 501(c)(3) | 2024 | $0 | $0 | 2025-12 |
| Choose Health Be Happy | Uppr Marlboro | 501(c)(3) | 2023 | $0 | $0 | 2024-12 |
| Citizens Rights and Heritage Groupinc | Lavale | 501(c)(4) | 2008 | $0 | $0 | 2025-12 |
| Citizens To Conserve and Restore Indian Creek Ccric Inc | Greenbelt | 501(c)(3) | 2000 | $0 | $0 | 2025-12 |
| Clean Montgomery County | Silver Spring | 501(c)(3) | 2026 | |||
| Clear Spring Garden Club | Clear Spring | 501(c)(3) | 2012 | $0 | $0 | 2026-06 |
| Climate Communications Coalition Inc | Frederick | 501(c)(3) | 2022 | $0 | $0 | 2025-12 |
| Climate First Inc | Takoma Park | 501(c)(3) | 2014 | $0 | $0 | 2025-12 |
| Clozynergy Inc | Uppr Marlboro | 501(c)(3) | 2012 | $0 | $0 | 2025-09 |
| Coalition Against Childhood Lead Poisoning Inc | Baltimore | 501(c)(4) | 2023 | $0 | $0 | 2025-12 |
| Common Resilience Partners | College Park | 501(c)(3) | 2022 | $0 | $0 | 2024-12 |
| Community Design Lab | Germantown | 501(c)(3) | 2025 | $0 | $0 | 2025-12 |
| Community Garden of Hampstead at Crossroads | Hampstead | 501(c)(3) | 2025 | |||
| Community Native Planting Project Inc | Bladensburg | 501(c)(3) | 2023 | $0 | $84,138 | 2025-12 |
| Community Research Inc | College Park | 501(c)(3) | 2010 | $0 | $0 | 2025-12 |
| Compostology Corp | Boyds | 501(c)(3) | 2023 | $0 | $0 | 2025-12 |
| Conservancy for Charles County Inc | Waldorf | 501(c)(3) | 1997 | $0 | $0 | 2025-12 |
| Conservation Montgomery | Silver Spring | 501(c)(3) | 2014 | $0 | $0 | 2025-12 |
| Consistent Life | Silver Spring | 501(c)(3) | 1993 | $0 | $0 | 2024-12 |
| Coral Reef Encounter Inc | Columbia | 501(c)(3) | 2023 | $0 | $0 | 2025-12 |
| Coral Triangle Conservation Fund | Takoma Park | 501(c)(3) | 2026 | $0 | $0 | 2025-12 |
| Corner Sanctuary Inc | Pocomoke City | 501(c)(3) | 2019 | $0 | $0 | 2025-12 |
| Cove Creek Conservation & Wildlife Foundation | Stevensville | 501(c)(3) | 2001 | $0 | $0 | 2025-12 |
| Cove Point Natural Heritage Trust Inc | Lusby | 501(c)(3) | 1995 | $7 million | 2025-12 | |
| Crab Creek Conservancy Inc | Annapolis | 501(c)(3) | 2021 | $0 | $0 | 2025-06 |
| Creative Climate Management Institute LTD | Chevy Chase | 501(c)(3) | 2022 | $0 | $0 | 2023-12 |
| Creative Education Association Inc | Annapolis | 501(c)(3) | 2002 | $0 | $0 | 2025-12 |
| Cricket Maze Cave Conservancy LTD | Bel Air | 501(c)(3) | 2023 | $0 | $0 | 2025-10 |
| D7etta Corporation | Baltimore | 501(c)(3) | 2023 | $0 | $0 | 2025-12 |
| Daughters of Union Veterans of the Civil War 1861-1865 | Jessup | 501(c)(3) | 2014 | $0 | $0 | 2025-08 |
| Daughters of Union Veterans of the Civil War 1861-1865 | Jessup | 501(c)(3) | 1956 | $0 | $0 | 2025-08 |
| Davis Homewood Foundation Inc | Salisbury | 501(c)(3) | 2024 | $80,000 | 2019-12 | |
| Dickerson Community Association | Dickerson | 501(c)(3) | 2004 | $0 | $0 | 2025-12 |
| District Cleanups | Annapolis | 501(c)(3) | 2022 | $0 | $0 | 2025-09 |
| Dorchester Citizens for Plannedgrowth Inc | Cambridge | 501(c)(3) | 2008 | $0 | $0 | 2024-12 |
| Eastern Shore Prescribed Burn Assoc Iation Inc | Snow Hill | 501(c)(3) | 2026 | |||
| Eco Moco Inc | Potomac | 501(c)(3) | 2024 | $0 | $0 | 2026-06 |
| Eco Viable | Potomac | 501(c)(3) | 2023 | $0 | $0 | 2024-12 |
| Ecolution | Laurel | 501(c)(3) | 2023 | $0 | $0 | 2025-12 |
| Ecoret Foundation | Beltsville | 501(c)(3) | 2026 | |||
| Educational Sustainability Mobilization | Silver Spring | 501(c)(3) | 2022 | $0 | $0 | 2025-12 |
| Elk Creeks Preservation Society Incorporated | Elk Mills | 501(c)(3) | 2014 | $0 | $0 | 2025-12 |
| Elk and North East Rivers Watershed Association | North East | 501(c)(3) | 2014 | $0 | $0 | 2025-12 |
| Energize Midatlantic | Shady Side | 501(c)(3) | 2025 | |||
| Ensprout Inc | Crofton | 501(c)(3) | 2023 | $0 | $0 | 2025-12 |
| Enterprise Green Accelerator Inc | Columbia | 501(c)(3) | 2025 | |||
| Environmental Certification Organization | Silver Spring | 501(c)(3) | 2024 | |||
| Environmental Crisis Center Inc | Hampstead | 501(c)(3) | 1997 | $0 | $0 | 2026-03 |
| Environmental Justice Oral History Project | Uppr Marlboro | 501(c)(3) | 2026 | $0 | $0 | 2025-12 |
| Environmental Solution International Inc | Baltimore | 501(c)(3) | 1990 | $0 | $0 | 2025-12 |
| Envirosynergy Incorporated | Bethesda | 501(c)(3) | 2004 | $0 | $0 | 2025-12 |
| Equestrian Partners in Conservation Inc | Boyds | 501(c)(3) | 2006 | $0 | $0 | 2025-12 |
| Existential Heroism Institute | College Park | 501(c)(3) | 2023 | $0 | $0 | 2024-06 |
| Eyes of Paint Branch Inc | Silver Spring | 501(c)(3) | 1994 | |||
| Farm Unity | Crofton | 501(c)(3) | 2023 | $0 | $0 | 2025-12 |
| Federate Garden Clubs of Maryland Inc | Westminster | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs Maryland Inc | Chestertown | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland | Parkton | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | Columbia | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | Reisterstown | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | Hvre de Grace | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | La Plata | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | Frederick | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | Frederick | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | Frederick | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | Baltimore | 501(c)(3) | 1985 | $0 | $1.1 million | 2024-12 |
| Federated Garden Clubs of Maryland Inc | Baltimore | 501(c)(3) | 1985 | $0 | $0 | 2026-06 |
| Federated Garden Clubs of Maryland Inc | Baltimore | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | Towson | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | Towson | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | Towson | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | Towson | 501(c)(3) | 1985 | $0 | $0 | 2026-05 |
| Federated Garden Clubs of Maryland Inc | Towson | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | Towson | 501(c)(3) | 1985 | $0 | $0 | 2025-06 |
| Federated Garden Clubs of Maryland Inc | Hagerstown | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | Annapolis | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | St Michaels | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | Ellicott City | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | Cockeysville | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | Berlin | 501(c)(3) | 2015 | $0 | $0 | 2026-02 |
| Federated Garden Clubs of Maryland Inc | Cambridge | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | Millersville | 501(c)(3) | 1985 | $0 | $0 | 2026-06 |
| Federated Garden Clubs of Maryland Inc | Shady Side | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | Cumberland | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | Forest Hill | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | White Hall | 501(c)(3) | 1985 | $0 | $0 | 2026-06 |
| Federated Garden Clubs of Maryland Inc | Parkville | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | Phoenix | 501(c)(3) | 1985 | $0 | $0 | 2026-06 |
| Federated Garden Clubs of Maryland Inc | Gibson Island | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | Chester | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | Taneytown | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Federated Garden Clubs of Maryland Inc | Coltons Point | 501(c)(3) | 1985 | $0 | $0 | 2025-12 |
| Fishtagged Inc | Germantown | 501(c)(3) | 2026 | |||
| Flatwoods Cemetery Maintenance | McHenry | 501(c)(3) | 2017 | $0 | $0 | 2026-04 |
| Frederick Green Inc | New Market | 501(c)(3) | 2022 | $0 | $0 | 2026-06 |
| Friends of Antietam Creek and Trovinger Mill | Hagerstown | 501(c)(3) | 2025 | |||
| Friends of Cabin John Creek Inc | Cabin John | 501(c)(3) | 2014 | $0 | $0 | 2025-12 |
| Friends of Cascade Lake Inc | Baltimore | 501(c)(3) | 2022 | $0 | $0 | 2024-12 |
| Friends of Chevy Chase Circle | Chevy Chase | 501(c)(3) | 2014 | $0 | $0 | 2025-12 |
| Friends of Downs Park Inc | Pasadena | 501(c)(3) | 2014 | $0 | $0 | 2025-12 |
| Friends of Environmental Education Inc | Kensington | 501(c)(3) | 2025 | $0 | $0 | 2025-12 |
| Friends of Greenbury Point Inc | Annapolis | 501(c)(3) | 2025 | $0 | $0 | 2025-12 |
| Friends of Harford Education Fund Inc | Bel Air | 501(c)(3) | 2007 | $0 | $0 | 2025-12 |
| Friends of Hart-Miller Island Inc | Middle River | 501(c)(3) | 2024 | $0 | $0 | 2025-12 |
| Friends of Hashawha Bear Branch | Westminster | 501(c)(3) | 2023 | $0 | $0 | 2026-06 |
| Friends of Helen Avalynne Tawes Garden Inc | Edgewater | 501(c)(3) | 2004 | $0 | $0 | 2025-12 |
| Friends of Liberty Reservoir | Finksburg | 501(c)(3) | 2024 | $0 | $0 | 2025-12 |
| Friends of Maydale Conservation Park Inc | Burtonsville | 501(c)(3) | 2021 | $0 | $0 | 2024-06 |
| Friends of Seneca Creek Patuxent River State Parks Inc | North Potomac | 501(c)(3) | 1997 | $0 | $0 | 2025-12 |
| Friends of Smallwood State Park Inc | Marbury | 501(c)(3) | 1996 | $0 | $0 | 2025-12 |
| Friends of Stevenson Inc | Baltimore | 501(c)(3) | 2015 | $0 | $1,000 | 2024-12 |
| Friends of Still Creek Inc | Greenbelt | 501(c)(3) | 2008 | $0 | $0 | 2025-12 |
| Friends of Ten Mile Creek and Little Seneca Reservoir | Clarksburg | 501(c)(3) | 2015 | $0 | $0 | 2025-12 |
| Friends of Waterford Park Inc | Frederick | 501(c)(3) | 2015 | $0 | $0 | 2025-06 |
| Friends of Wormans Mill Park | Frederick | 501(c)(3) | 2025 | $0 | $0 | 2025-12 |
| Friends of the Bohemia Inc | Chesapeake Cy | 501(c)(3) | 2015 | $0 | $0 | 2025-12 |
| Friends of the Ecosystem Restoration Movement Inc | Silver Spring | 501(c)(3) | 2025 | $0 | $0 | 2025-12 |
| Friends of the Maryland State Forests and Parks Inc | Ocean City | 501(c)(3) | 1998 | $0 | $0 | 2025-12 |
| Friends of the Nanticoke River | Nanticoke | 501(c)(3) | 2010 | $0 | $0 | 2025-12 |
| Friends of the North East Creek Inc | North East | 501(c)(3) | 2020 | $0 | $0 | 2025-12 |
| Fski Community Link | Chester | 501(c)(3) | 2024 | |||
| Funam Development Association USA Inc | Germantown | 501(c)(3) | 2024 | $0 | $0 | 2025-12 |
| Garden Club of Chevy Chase Inc | Chevy Chase | 501(c)(3) | 2024 | $0 | $0 | 2025-06 |
| Garden Club of Rock Hall | Chestertown | 501(c)(3) | 2015 | $0 | $0 | 2025-08 |
| Ghetto Love Inc | Baltimore | 501(c)(3) | 2020 | $0 | $0 | 2023-06 |
| Giving Is Living | District HTS | 501(c)(3) | 2023 | $0 | $0 | 2025-12 |
| Global Water Promise Corp | Baltimore | 501(c)(3) | 2018 | $0 | $0 | 2025-12 |
| Goode Earth Foundation | Capitol HGTS | 501(c)(3) | 2025 | $0 | $0 | 2024-12 |
| Gray Manor & Northshire Community Association | Dundalk | 501(c)(3) | 2012 | $0 | $0 | 2025-12 |
| Greater Sandy Spring Green Space Inc | Sandy Spring | 501(c)(3) | 1998 | $0 | $0 | 2025-12 |
| Greater Washington Aquatic Plants Association | Laurel | 501(c)(3) | 2019 | $0 | $0 | 2025-12 |
| Greater Waverly Coalition Inc | Baltimore | 501(c)(3) | 2022 | $0 | $0 | 2025-12 |
| Green Burial Association of Maryland Inc | Cockeysville | 501(c)(3) | 2016 | $0 | $0 | 2025-12 |
| Green Can Recycling Inc | North East | 501(c)(3) | 2019 | $0 | $0 | 2024-12 |
| Green Deshis Inc | Ellicott City | 501(c)(3) | 2024 | $0 | $0 | 2020-12 |
| Green Habitat | Fort Washington | 501(c)(3) | 2016 | $0 | $0 | 2023-12 |
| Green Haiti International Ghi LTD | Baltimore | 501(c)(3) | 2023 | $0 | $0 | 2023-12 |
| Green Infrastructure Leadership Exchange | Parkville | 501(c)(3) | 2026 | $0 | $0 | 2025-12 |
| Green Spark Inc | Laurel | 501(c)(3) | 2024 | $0 | $0 | 2025-12 |
| Green Steps Partner Inc | Parkville | 501(c)(3) | 2016 | $0 | $0 | 2024-12 |
| Greenhood Corporation | College Park | 501(c)(3) | 2026 | |||
| Greennonprofits Org Inc | Columbia | 501(c)(3) | 2008 | $0 | $0 | 2025-12 |
| Greentrust Alliance Inc | Cockeysville | 501(c)(3) | 2026 | $3.8 million | 2024-12 | |
| Growth Action Network of Anne Arundel County Inc | Arnold | 501(c)(3) | 2014 | $0 | $0 | 2025-12 |
| H2eco Foundation Inc | Towson | 501(c)(3) | 2025 | $0 | $0 | 2025-12 |
| HBC Dream Foundation | Baltimore | 501(c)(3) | 2025 | |||
| Hanover Road Association Inc | Upperco | 501(c)(3) | 2014 | $0 | $0 | 2024-12 |
| Harford County Climate Action | Bel Air | 501(c)(3) | 2015 | $0 | $0 | 2025-10 |
| Head of Chesapeake Watershed Alliance Inc | Hvre de Grace | 501(c)(3) | 2020 | $0 | $0 | 2025-12 |
| Help Our Marine Environment Inc | Chevy Chase | 501(c)(3) | 2013 | $0 | $0 | 2025-12 |
| Henry Sears Foundation Inc | Chestertown | 501(c)(3) | 1996 | $1.1 million | 2025-12 | |
| High 5 Initiative | North East | 501(c)(3) | 2019 | $0 | $0 | 2025-12 |
| Homeland Community Foundation | Baltimore | 501(c)(3) | 1999 | $0 | $0 | 2025-12 |
| Homeland Garden Club | Baltimore | 501(c)(3) | 2024 | $0 | $0 | 2023-12 |
| House of Prayer for All People Elijah Endtime Ministries Inc | Port Deposit | 501(c)(3) | 2022 | $0 | $0 | 2024-12 |
| Hyattsville Horticultural Society | Hyattsville | 501(c)(3) | 2017 | $0 | $0 | 2025-12 |
| Institute for Preservation and Progress Inc | Parkton | 501(c)(3) | 2025 | |||
| Interest Custodian Community Cleani NG Inc | Baltimore | 501(c)(3) | 2026 | |||
| Iucn Academy of Environmental Law LTD | Baltimore | 501(c)(3) | 2020 | $0 | $1 | 2025-06 |
| James Edward Darby | Chase | 501(c)(3) | 2026 | |||
| Joe Brooks Foundation for Conservation and Outdoor Education | Towson | 501(c)(3) | 2016 | $14,150 | 2025-12 | |
| John Penn Whitescarver Sr Foundation Inc | Bel Air | 501(c)(3) | 1999 | $1,950 | 2025-12 | |
| John Street Park Association | Baltimore | 501(c)(3) | 1990 | $0 | $0 | 2025-12 |
| Keep Somerset Beautiful | Westover | 501(c)(3) | 2019 | $0 | $0 | 2024-12 |
| Kensington Land Trust Inc | Kensington | 501(c)(3) | 1992 | $0 | $0 | 2024-12 |
| Kent Island Beach Cleanups Inc | Stevensville | 501(c)(3) | 2015 | $0 | $0 | 2025-12 |
| Kent Island Community Garden | Chester | 501(c)(3) | 2024 | $0 | $0 | 2025-12 |
| Laurel for the Patuxent | Laurel | 501(c)(3) | 2020 | $0 | $7,230 | 2025-12 |
| Lead Manage Conserve Inc | Chevy Chase | 501(c)(3) | 2024 | $0 | $0 | 2025-12 |
| Leaflearn Environmental Education I Nstitute Corporation | Potomac | 501(c)(3) | 2026 | |||
| Life4sofala Foundation Inc | Cambridge | 501(c)(3) | 2011 | $0 | $0 | 2025-12 |
| Literally Clean Corp | Clinton | 501(c)(3) | 2026 | |||
| Little Magothy River Association Inc | Annapolis | 501(c)(3) | 2024 | $0 | $0 | 2025-06 |
| Malachi Water Winds Woods Foundation Inc | Reisterstown | 501(c)(3) | 2024 | $0 | $0 | 2025-12 |
| Marshy Point Nature Center Council | Middle River | 501(c)(3) | 2017 | $0 | $0 | 2025-12 |
| Marumsco Creek Wildlife Foundation Inc | Pocomoke City | 501(c)(3) | 2000 | $81,665 | 2025-08 | |
| Maryland Chapter of the American Chestnut Foundation Inc | Takoma Park | 501(c)(3) | 2004 | $0 | $0 | 2025-12 |
| Maryland Fossil Finders | Owings Mills | 501(c)(3) | 2025 | |||
| Maryland Orchid Society Inc | Mount Airy | 501(c)(3) | 2021 | $0 | $0 | 2025-08 |
| Maryland Stream Restoration Association | Gambrills | 501(c)(3) | 2014 | $0 | $0 | 2025-12 |
| Maryland Wildlife Crime Stoppers Inc | Annapolis | 501(c)(3) | 2018 | $0 | $0 | 2025-12 |
| Maryland-Dc Composting Council | Cockeysville | 501(c)(3) | 2024 | $0 | $0 | 2026-07 |
| Mason Springs Conservancy Inc | Waldorf | 501(c)(3) | 2006 | $0 | $0 | 2024-12 |
| Mattawoman Watershed Society | Accokeek | 501(c)(3) | 2009 | $0 | $0 | 2024-12 |
| Mid Atlantic Region Environmental Professionals | Rockville | 501(c)(3) | 2015 | $0 | $0 | 2024-12 |
| Mindful Maryland | Bowie | 501(c)(3) | 2024 | $0 | $0 | 2025-12 |
| Misty of Chincoteague Foundation | Solomons | 501(c)(3) | 1990 | $0 | $0 | 2025-12 |
| Mother Earth Project Incorporated | Bethesda | 501(c)(3) | 2018 | $0 | $0 | 2024-12 |
| NCR Hereford Volunteers Association Inc of Gunpowder Falls State Park | Monkton | 501(c)(3) | 2011 | $0 | $0 | 2025-12 |
| Nanjemoy Vision Inc | Nanjemoy | 501(c)(3) | 2012 | $0 | $0 | 2025-12 |
| Nanjemoy-Potomac Enviromental Coalition Inc | Nanjemoy | 501(c)(3) | 2001 | $0 | $0 | 2025-12 |
| National Pollinator Health Alliance | University Pa | 501(c)(3) | 2026 | |||
| Nationwide Environmental Testing in C | Rockville | 501(c)(3) | 2026 | |||
| Native Grassland Conservancy Inc | Uppr Marlboro | 501(c)(3) | 2010 | $0 | $0 | 2025-12 |
| Neeld Estate Citizens Association | Huntingtown | 501(c)(4) | 2022 | $0 | $0 | 2025-12 |
| Neighbors of the Northwest Branch Inc | Silver Spring | 501(c)(3) | 2004 | $0 | $0 | 2024-12 |
| New Israel American Education Fund Inc | Bethesda | 501(c)(3) | 2020 | $0 | $11,981 | 2024-12 |
| North County Preservation Incorporated | Kingsville | 501(c)(3) | 2004 | |||
| Nurture Natives | La Plata | 501(c)(3) | 2023 | $0 | $0 | 2025-07 |
| O Lab Inc | Takoma Park | 501(c)(3) | 2026 | $0 | $0 | 2025-12 |
| Our Children Future | Oxon Hill | 501(c)(3) | 2026 | |||
| Partners for Nature Inc | Chevy Chase | 501(c)(3) | 2025 | |||
| Patuxent Rediscovered Corporation | Benedict | 501(c)(3) | 2025 | |||
| Peoples Environmental Action and Re Silience Learning Inc | Baltimore | 501(c)(3) | 2026 | |||
| Piedmont Environmental and Education Foundation Inc | Barnesville | 501(c)(3) | 2006 | $0 | $0 | 2025-12 |
| Piedmont Learning Center Inc | Gwynn Oak | 501(c)(3) | 2022 | $0 | $0 | 2025-12 |
| Pikesville Garden Club Inc | Baltimore | 501(c)(3) | 2015 | $0 | $0 | 2025-12 |
| Piscataway Land Trust Inc | Fort Washington | 501(c)(3) | 2023 | $0 | $0 | 2025-12 |
| Plastic Free Qac Inc | Grasonville | 501(c)(3) | 2018 | $0 | $0 | 2025-06 |
| Point Pleasant Foundation | Bozman | 501(c)(3) | 2023 | $9.6 million | 2024-12 | |
| Poolesville Green | Poolesville | 501(c)(3) | 2010 | $0 | $0 | 2025-12 |
| Potomac Village Garden Club | Potomac | 501(c)(3) | 2023 | $36,312 | 2025-06 | |
| Proactive Science Inc | Lusby | 501(c)(3) | 2006 | $0 | $0 | 2024-12 |
| Project Green Sweep | Potomac | 501(c)(3) | 2025 | $0 | $0 | 2025-12 |
| Repowerus Inc | Kensington | 501(c)(3) | 2024 | $0 | $0 | 2024-12 |
| Resilient Power Research Foundation Limited | Baltimore | 501(c)(3) | 2026 | |||
| Restore the Climate Inc | Rockville | 501(c)(3) | 2024 | $0 | $0 | 2025-12 |
| Revive Saree Corp | Boyds | 501(c)(3) | 2025 | $0 | $0 | 2025-12 |
| Rise N Shine Foundation Inc | Clarksburg | 501(c)(3) | 2019 | $0 | $0 | 2025-12 |
| Rural Energy Alliance | Mechanicsvlle | 501(c)(3) | 2026 | |||
| SLM Native Bloom Haven | Laurel | 501(c)(3) | 2026 | $0 | $0 | 2025-12 |
| Sacred Forest Conservancy Inc | Baltimore | 501(c)(3) | 2026 | |||
| Salvaged Worlds | Hagerstown | 501(c)(3) | 2024 | |||
| Save Our Sustainable Hyattsville | Hyattsville | 501(c)(3) | 2022 | $0 | $0 | 2024-12 |
| Savefairhill Inc | Elkton | 501(c)(3) | 2014 | $0 | $0 | 2025-12 |
| Saving Grace Ministries in Christ | Baltimore | 501(c)(3) | 2012 | $0 | $0 | 2024-12 |
| Seaquality Foundation Inc | Montgomry VLG | 501(c)(3) | 2026 | |||
| Sefra Intiative | N Bethesda | 501(c)(3) | 2026 | |||
| Seneca Creek Watershed Partners Inc | Gaithersburg | 501(c)(3) | 2015 | $0 | $0 | 2024-12 |
| Serenity Ridge Nature Preserve and Arboretum Inc | Windsor Mill | 501(c)(3) | 2024 | $0 | $0 | 2025-12 |
| Sligo Creek Neighbors for A Sustainable Community | Silver Spring | 501(c)(3) | 2016 | $0 | $0 | 2025-12 |
| Sligo Environmental Agency | Baltimore | 501(c)(3) | 2024 | |||
| Sludge Hub & Company | Baltimore | 501(c)(3) | 2022 | $0 | $0 | 2024-12 |
| Society Hill Garden Club of Breton Bay | Leonardtown | 501(c)(3) | 2022 | $0 | $0 | 2025-12 |
| Soil & Water Conservation Society Maryland Old Line Chapter | La Plata | 501(c)(3) | 2026 | |||
| Solar Consumer Protection Coalition Inc | Columbia | 501(c)(3) | 2025 | |||
| Soulusa Baylife | Berwyn HTS | 501(c)(3) | 2026 |
Read from the IRS Exempt Organizations Business Master File, updated by the IRS on October 24, 2026 and rebuilt here every morning. Revenue and assets are from each organization's latest filing as the IRS lists it; the IRS record is the official one. Organizations only: no people are named on these pages.