| Coalition to Restore Coastal LouisianaEIN 72-1115589 | Environment | LA | $2,240,672Small | 85.48 |
| Coastal Conservation AssociationEIN 74-1984482 | Environment | TX | $13,776,533Large | 81.37 |
| Coastal Conservation LeagueEIN 57-0887278 | Environment | SC | $3,691,863Mid-sized | 91.84 |
| Coming CleanEIN 04-3429794 | Environment | VT | $984,122Small | 82.69 |
| Committee For A Constructive TomorrowEIN 52-1462893 | Environment | DC | $1,754,758Small | 70.10 |
| Communities for a Better EnvironmentEIN 94-2998086 | Environment | CA | $2,066,472Small | 83.88 |
| Community Environmental CouncilEIN 94-1728064 | Environment | CA | $1,225,334Small | 87.24 |
| Connecticut Audubon SocietyEIN 06-0653531 | Environment | CT | $3,731,785Mid-sized | 94.19 |
| Connecticut Fund for the EnvironmentEIN 06-0990195 | Environment | CT | $3,663,406Mid-sized | 92.37 |
| Conservancy of Southwest FloridaEIN 59-1157084 | Environment | FL | $8,102,079Mid-sized | 93.89 |
| Conservation Colorado Education FundEIN 84-0614285 | Environment | CO | $1,902,201Small | 92.20 |
| Conservation Foundation of the Gulf CoastEIN 20-0345249 | Environment | FL | $1,097,099Small | 95.85 |
| Conservation InternationalEIN 52-1497470 | Environment | VA | $149,806,220Large | 95.88 |
| Conservation Lands FoundationEIN 20-8924520 | Environment | CO | $7,028,672Mid-sized | 94.33 |
| Conservation Law FoundationEIN 04-6149986 | Environment | MA | $9,439,409Mid-sized | 91.21 |
| Conservation MinnesotaEIN 41-2017329 | Environment | MN | $1,455,520Small | 88.06 |
| Conservation NorthwestEIN 94-3091547 | Environment | WA | $2,055,902Small | 87.29 |
| Conservation Strategy FundEIN 94-3294843 | Environment | DC | $2,079,533Small | 87.92 |
| Coral Reef AllianceEIN 94-3211245 | Environment | CA | $3,119,480Small | 92.03 |
| Cultural Landscape FoundationEIN 52-2092229 | Environment | DC | $1,301,543Small | 86.63 |
| Delaware Riverkeeper NetworkEIN 74-3255972 | Environment | PA | $2,931,825Small | 88.44 |
| Dogwood AllianceEIN 56-2139120 | Environment | NC | $1,552,587Small | 88.31 |
| Earth Conservation CorpsEIN 52-1683270 | Environment | DC | $350,700Small | 74.09 |
| Earth Day NetworkEIN 13-3798288 | Environment | DC | $2,970,282Small | 91.94 |
| Earth Island InstituteEIN 94-2889684 | Environment | CA | $9,751,020Mid-sized | 88.24 |
| EarthEcho InternationalEIN 95-4789334 | Environment | DC | $698,764Small | 82.66 |
| EarthjusticeEIN 94-1730465 | Environment | CA | $51,564,754Large | 94.85 |
| EarthShareEIN 52-1601960 | Environment | MD | $6,743,365Mid-sized | 76.31 |
| EarthShare CaliforniaEIN 94-2840364 | Environment | CA | $1,349,632Small | 73.23 |
| EarthShare GeorgiaEIN 58-2022001 | Environment | GA | $635,892Small | 80.68 |
| EarthShare TexasEIN 74-2627643 | Environment | TX | $407,224Small | 84.86 |
| EARTHWORKSEIN 52-1557765 | Environment | DC | $3,301,953Small | 94.74 |
| ecoAmericaEIN 20-3895611 | Environment | DC | $4,482,513Mid-sized | 88.77 |
| EcoLogic Development FundEIN 25-1704582 | Environment | MA | $1,487,137Small | 81.51 |
| Ecology CenterEIN 38-1912803 | Environment | MI | $1,941,562Small | 93.09 |
| EcotrustEIN 93-1050144 | Environment | OR | $5,895,078Mid-sized | 88.19 |
| Emerald Necklace ConservancyEIN 04-3414988 | Environment | MA | $1,687,443Small | 83.01 |
| Environment America Research and Policy CenterEIN 13-4339865 | Environment | CO | $3,179,487Small | 83.13 |
| Environmental Advocates of New YorkEIN 22-2360736 | Environment | NY | $1,251,586Small | 99.79 |
| Environmental and Energy Study InstituteEIN 52-1268030 | Environment | DC | $1,296,571Small | 100.00 |
| Environmental Defense CenterEIN 77-0061994 | Environment | CA | $1,135,564Small | 90.57 |
| Environmental Grantmakers AssociationEIN 20-8817646 | Environment | NY | $2,539,563Small | 91.44 |
| Environmental Health CoalitionEIN 95-3798792 | Environment | CA | $3,829,007Mid-sized | 86.60 |
| Environmental InitiativeEIN 41-1718834 | Environment | MN | $2,064,185Small | 96.07 |
| Environmental Integrity ProjectEIN 20-1326922 | Environment | DC | $3,168,637Small | 84.42 |
| Environmental Investigation AgencyEIN 52-1654284 | Environment | DC | $4,791,938Mid-sized | 89.39 |
| Environmental Law Alliance WorldwideEIN 94-3116602 | Environment | OR | $1,816,495Small | 95.34 |
| Environmental Law and Policy CenterEIN 36-3866530 | Environment | IL | $6,344,275Mid-sized | 93.30 |
| Environmental Law InstituteEIN 52-0901863 | Environment | DC | $5,604,514Mid-sized | 92.44 |
| Environmental Research and Education FoundationEIN 52-1804051 | Environment | NC | $2,511,072Small | 95.50 |
| Environmental Working GroupEIN 52-2148600 | Environment | DC | $9,318,340Mid-sized | 91.51 |
| Everglades FoundationEIN 59-3228899 | Environment | FL | $8,149,416Mid-sized | 91.03 |
| Fontenelle ForestEIN 47-6026109 | Environment | NE | $2,448,954Small | 87.95 |
| Forest TrendsEIN 52-2135531 | Environment | DC | $10,556,855Mid-sized | 86.54 |
| Friends of the Arava InstituteEIN 11-3485736 | Environment | MA | $1,440,708Small | 82.81 |
| Friends of the EarthEIN 23-7420660 | Environment | DC | $10,291,770Mid-sized | 94.64 |
| Friends of the Mississippi RiverEIN 41-1763226 | Environment | MN | $2,220,748Small | 88.00 |
| Friends of the RiverEIN 94-2400210 | Environment | CA | $457,705Small | 80.53 |
| Galapagos ConservancyEIN 13-3281486 | Environment | VA | $4,584,984Mid-sized | 93.13 |
| Galveston Bay FoundationEIN 76-0279876 | Environment | TX | $6,699,575Mid-sized | 92.92 |