| Earthwatch InstituteEIN 23-7168440 | Research and Public Policy | MA | $7,458,378Mid-sized | 86.99 |
| Economic Policy InstituteEIN 52-1368964 | Research and Public Policy | DC | $6,502,386Mid-sized | 90.38 |
| Encore.orgEIN 94-3274339 | Research and Public Policy | CA | $6,224,565Mid-sized | 90.71 |
| Ethics and Public Policy CenterEIN 52-1162185 | Research and Public Policy | DC | $3,827,567Mid-sized | 89.98 |
| Everytown for Gun Safety Support FundEIN 26-1598353 | Research and Public Policy | NY | $15,515,941Large | 76.39 |
| Families USA FoundationEIN 04-2730934 | Research and Public Policy | DC | $8,981,636Mid-sized | 82.60 |
| Family Online Safety InstituteEIN 52-2210323 | Research and Public Policy | DC | $1,588,755Small | 75.34 |
| Food Research & Action CenterEIN 23-7200739 | Research and Public Policy | DC | $11,894,182Mid-sized | 86.79 |
| Foundation for Defense of DemocraciesEIN 13-4174402 | Research and Public Policy | DC | $11,705,479Mid-sized | 89.22 |
| Foundation for Economic EducationEIN 13-6006960 | Research and Public Policy | GA | $3,968,619Mid-sized | 82.80 |
| Franklin News FoundationEIN 26-4066298 | Research and Public Policy | IL | $4,189,004Mid-sized | 66.66 |
| Freedom FoundationEIN 94-3136961 | Research and Public Policy | WA | $4,123,043Mid-sized | 78.12 |
| Global Footprint NetworkEIN 73-1672982 | Research and Public Policy | CA | $1,905,405Small | 82.88 |
| Global Philanthropy PartnershipEIN 56-2342600 | Research and Public Policy | IL | $4,493,605Mid-sized | 84.34 |
| Headwaters EconomicsEIN 74-3171967 | Research and Public Policy | MT | $2,292,223Small | 84.34 |
| Health Policy Institute of OhioEIN 30-0186863 | Research and Public Policy | OH | $1,343,224Small | 89.74 |
| Hope Street GroupEIN 45-0497577 | Research and Public Policy | DC | $4,944,604Mid-sized | 80.75 |
| Illinois Policy InstituteEIN 41-2057028 | Research and Public Policy | IL | $6,963,067Mid-sized | 84.41 |
| Independence InstituteEIN 84-0990300 | Research and Public Policy | CO | $2,907,995Small | 91.15 |
| Institute for Agriculture and Trade PolicyEIN 36-3501938 | Research and Public Policy | MN | $1,790,307Small | 83.92 |
| Institute for America's FutureEIN 52-1971942 | Research and Public Policy | DC | $2,915,846Small | 83.56 |
| Institute for American ValuesEIN 13-3400377 | Research and Public Policy | NY | $626,271Small | 62.30 |
| Institute for Energy ResearchEIN 76-0149778 | Research and Public Policy | DC | $1,666,571Small | 89.48 |
| Institute for Local Self-RelianceEIN 23-7394104 | Research and Public Policy | DC | $1,525,548Small | 91.75 |
| Institute for Policy StudiesEIN 52-0788947 | Research and Public Policy | DC | $3,889,771Mid-sized | 94.21 |
| Institute for the Study of WarEIN 26-0273675 | Research and Public Policy | DC | $1,843,667Small | 81.77 |
| Institute for Women's Policy ResearchEIN 52-1549572 | Research and Public Policy | DC | $3,176,103Small | 86.79 |
| Institute of Noetic SciencesEIN 23-7236986 | Research and Public Policy | CA | $5,024,895Mid-sized | 87.56 |
| Institute on Religion and Public LifeEIN 52-1628303 | Research and Public Policy | NY | $2,861,837Small | 70.49 |
| Institute on Taxation and Economic PolicyEIN 04-2688165 | Research and Public Policy | DC | $1,804,899Small | 93.91 |
| Iowa Citizens for Community ImprovementEIN 42-1110721 | Research and Public Policy | IA | $1,101,924Small | 88.90 |
| Jewish Council for Public AffairsEIN 13-1624104 | Research and Public Policy | NY | $3,662,470Mid-sized | 72.38 |
| John Locke FoundationEIN 56-1656943 | Research and Public Policy | NC | $3,396,192Small | 80.47 |
| Keystone Policy CenterEIN 84-0688506 | Research and Public Policy | CO | $3,705,939Mid-sized | 78.10 |
| League of American BicyclistsEIN 36-6206225 | Research and Public Policy | DC | $1,587,429Small | 81.45 |
| Lexington InstituteEIN 54-1880642 | Research and Public Policy | VA | $2,015,906Small | 70.79 |
| LiveWell ColoradoEIN 26-2464764 | Research and Public Policy | CO | $4,006,804Mid-sized | 86.84 |
| Long Now FoundationEIN 68-0384748 | Research and Public Policy | CA | $3,028,507Small | 90.03 |
| Lowell ObservatoryEIN 86-0098918 | Research and Public Policy | AZ | $12,648,803Mid-sized | 88.56 |
| Mackinac CenterEIN 38-2701547 | Research and Public Policy | MI | $6,608,146Mid-sized | 92.92 |
| Manhattan Institute for Policy ResearchEIN 13-2912529 | Research and Public Policy | NY | $18,832,278Large | 94.25 |
| Marijuana Policy Project FoundationEIN 52-1975211 | Research and Public Policy | DC | $2,866,841Small | 77.62 |
| Marine Biological LaboratoryEIN 04-2104690 | Research and Public Policy | MA | $42,842,812Large | 86.19 |
| MassINCEIN 04-3271457 | Research and Public Policy | MA | $1,950,185Small | 83.15 |
| Media Matters for AmericaEIN 47-0928008 | Research and Public Policy | DC | $10,867,830Mid-sized | 75.10 |
| Mercatus CenterEIN 54-1436224 | Research and Public Policy | VA | $27,582,187Large | 88.81 |
| Michigan League for Public PolicyEIN 38-1360557 | Research and Public Policy | MI | $1,796,596Small | 92.85 |
| Mid-Atlantic Foundation for Safety and EducationEIN 23-3100128 | Research and Public Policy | DE | $1,089,582Small | 82.32 |
| Middle East ForumEIN 23-7749796 | Research and Public Policy | PA | $3,682,718Mid-sized | 88.61 |
| Mind & Life InstituteEIN 77-0284767 | Research and Public Policy | VA | $3,552,029Mid-sized | 89.22 |
| Mises InstituteEIN 52-1263436 | Research and Public Policy | AL | $4,165,289Mid-sized | 94.70 |
| MN Community MeasurementEIN 35-2246162 | Research and Public Policy | MN | $3,570,442Mid-sized | 83.18 |
| Mote Marine LaboratoryEIN 59-0756643 | Research and Public Policy | FL | $22,091,552Large | 92.18 |
| Mount Desert Island Biological LaboratoryEIN 01-0202467 | Research and Public Policy | ME | $11,741,518Mid-sized | 92.61 |
| Mount Washington ObservatoryEIN 02-0225135 | Research and Public Policy | NH | $2,066,258Small | 81.07 |
| NALEO Educational FundEIN 52-1212849 | Research and Public Policy | CA | $8,307,589Mid-sized | 86.84 |
| National Academy of Engineering FundEIN 23-7284092 | Research and Public Policy | DC | $9,369,619Mid-sized | 80.56 |
| National Bureau of Asian ResearchEIN 91-1444105 | Research and Public Policy | WA | $5,395,449Mid-sized | 81.05 |
| National Center for Policy AnalysisEIN 75-1804932 | Research and Public Policy | TX | $3,263,918Small | 59.74 |
| National Coalition for Cancer SurvivorshipEIN 85-0357897 | Research and Public Policy | MD | $2,005,063Small | 78.86 |