| Natural Resources Defense CouncilEIN 13-2654926 | Environment | NY | $128,772,908Large | 93.49 |
| Nature and Culture InternationalEIN 33-0773524 | Environment | CA | $6,361,508Mid-sized | 93.91 |
| NatureServeEIN 52-1884438 | Environment | VA | $8,421,554Mid-sized | 84.93 |
| NC WARNEIN 56-1734433 | Environment | NC | $1,625,630Small | 75.89 |
| New Buildings InstituteEIN 68-0401509 | Environment | OR | $2,723,011Small | 89.68 |
| New England Forestry FoundationEIN 04-2024022 | Environment | MA | $2,723,042Small | 89.97 |
| New Hampshire AudubonEIN 02-6005322 | Environment | NH | $2,319,775Small | 84.53 |
| New Jersey Audubon SocietyEIN 22-1539642 | Environment | NJ | $6,683,422Mid-sized | 94.64 |
| New Mexico Wilderness AllianceEIN 85-0457916 | Environment | NM | $1,183,856Small | 93.26 |
| North Carolina Coastal FederationEIN 58-1494098 | Environment | NC | $4,990,549Mid-sized | 97.68 |
| North Carolina Sustainable Energy AssociationEIN 58-1342588 | Environment | NC | $2,583,714Small | 89.27 |
| North Cascades InstituteEIN 91-1327775 | Environment | WA | $3,940,440Mid-sized | 95.46 |
| Northeast Sustainable Energy AssociationEIN 23-7437161 | Environment | MA | $1,399,599Small | 74.96 |
| Northern Plains Resource CouncilEIN 81-0367205 | Environment | MT | $1,377,941Small | 94.34 |
| Occidental Arts and Ecology CenterEIN 68-0359676 | Environment | CA | $1,944,634Small | 77.79 |
| Ocean ConservancyEIN 23-7245152 | Environment | DC | $23,984,534Large | 91.97 |
| Ocean Research & Conservation AssociationEIN 20-0901011 | Environment | FL | $1,613,797Small | 72.08 |
| OceanaEIN 51-0401308 | Environment | DC | $37,880,581Large | 94.11 |
| Ohio Environmental CouncilEIN 31-0805578 | Environment | OH | $2,085,734Small | 83.94 |
| Orange County CoastkeeperEIN 33-0847892 | Environment | CA | $1,772,988Small | 94.74 |
| Oregon Natural Desert AssociationEIN 94-3098621 | Environment | OR | $1,631,248Small | 94.83 |
| Organic Consumers AssociationEIN 41-1908341 | Environment | MN | $3,495,920Small | 87.44 |
| Pacific Crest Trail AssociationEIN 33-0051202 | Environment | CA | $3,359,863Small | 81.60 |
| Pacific EnvironmentEIN 94-2628924 | Environment | CA | $1,330,701Small | 86.58 |
| PATH FoundationEIN 58-1949696 | Environment | GA | $12,274,297Mid-sized | 96.23 |
| PennFutureEIN 31-1607866 | Environment | PA | $3,214,540Small | 90.24 |
| Pennsylvania Environmental CouncilEIN 23-7286159 | Environment | PA | $3,284,015Small | 89.71 |
| Pinchot Institute for ConservationEIN 52-1935342 | Environment | DC | $1,567,804Small | 77.83 |
| Pinelands Preservation AllianceEIN 52-1641512 | Environment | NJ | $1,787,425Small | 91.11 |
| Planet AidEIN 04-3348171 | Environment | MD | $40,116,928Large | 79.87 |
| Property and Environment Research CenterEIN 81-0393444 | Environment | MT | $2,268,821Small | 90.88 |
| Public Employees for Environmental ResponsibilityEIN 93-1102740 | Environment | MD | $829,164Small | 91.26 |
| Pure EarthEIN 13-4075779 | Environment | NY | $4,713,887Mid-sized | 97.74 |
| Quebec-Labrador FoundationEIN 13-6155399 | Environment | MA | $1,895,344Small | 92.79 |
| Rails-To-Trails ConservancyEIN 52-1437006 | Environment | DC | $9,232,373Mid-sized | 90.68 |
| Rainforest Action NetworkEIN 94-3045180 | Environment | CA | $6,840,501Mid-sized | 89.83 |
| Rainforest AllianceEIN 13-3377893 | Environment | NY | $39,968,460Large | 79.81 |
| Rainforest Foundation USEIN 95-1622945 | Environment | NY | $2,617,359Small | 98.23 |
| Rainforest TrustEIN 13-3500609 | Environment | VA | $16,200,766Large | 94.69 |
| RareEIN 23-7380563 | Environment | VA | $25,106,435Large | 92.29 |
| Regional Trail CorporationEIN 25-1660116 | Environment | PA | $874,198Small | 83.96 |
| Resource CentralEIN 84-0808982 | Environment | CO | $2,340,605Small | 92.51 |
| Resources for the FutureEIN 53-0220900 | Environment | DC | $13,755,089Large | 89.69 |
| River NetworkEIN 93-0969979 | Environment | CO | $2,276,677Small | 88.96 |
| RiverkeeperEIN 13-3204621 | Environment | NY | $4,274,476Mid-sized | 93.25 |
| Rocky Mountain ConservancyEIN 84-0472090 | Environment | CO | $3,017,070Small | 96.63 |
| Rocky Mountain InstituteEIN 74-2244146 | Environment | CO | $33,402,821Large | 94.57 |
| Rose Foundation for Communities and the EnvironmentEIN 94-3179772 | Environment | CA | $7,448,602Mid-sized | 100.00 |
| Rural Advancement Foundation International-USAEIN 56-1704863 | Environment | NC | $2,116,129Small | 100.00 |
| San Diego CoastkeeperEIN 33-0647946 | Environment | CA | $668,734Small | 78.81 |
| San Francisco BaykeeperEIN 68-0120240 | Environment | CA | $1,512,332Small | 84.75 |
| San Joaquin River Parkway and Conservation TrustEIN 77-0196692 | Environment | CA | $1,749,897Small | 90.56 |
| Sanibel-Captiva Conservation FoundationEIN 59-1205087 | Environment | FL | $3,095,476Small | 90.45 |
| Schlitz Audubon Nature CenterEIN 39-1231819 | Environment | WI | $2,897,570Small | 90.69 |
| Seattle Audubon SocietyEIN 91-6009716 | Environment | WA | $1,068,105Small | 86.75 |
| Second NatureEIN 04-3195772 | Environment | MA | $1,691,248Small | 89.82 |
| Seed Savers ExchangeEIN 43-1214133 | Environment | IA | $5,385,772Mid-sized | 84.73 |
| Sierra Club FoundationEIN 94-6069890 | Environment | CA | $72,890,348Large | 95.21 |
| Sierra Nevada AllianceEIN 77-0343881 | Environment | CA | $825,345Small | 79.38 |
| Sky Island AllianceEIN 86-0796748 | Environment | AZ | $1,171,111Small | 97.70 |