| Congressional Black Caucus FoundationEIN 52-1160561 | Research and Public Policy | DC | $7,300,039Mid-sized | 89.01 |
| Connect2Help 2-1-1EIN 31-1216792 | Human Services | IN | $2,490,328Small | 88.76 |
| Connecticut Association for Human ServicesEIN 06-0653158 | Research and Public Policy | CT | $1,624,056Small | 86.93 |
| Connecticut Cancer FoundationEIN 06-1240574 | Health | CT | $942,787Small | 88.74 |
| Connecticut Historical SocietyEIN 06-6026012 | Arts, Culture, Humanities | CT | $3,041,718Small | 85.24 |
| Connecticut Humane SocietyEIN 06-0667605 | Animals | CT | $8,990,903Mid-sized | 89.17 |
| Connecticut Public BroadcastingEIN 06-0758938 | Arts, Culture, Humanities | CT | $22,123,694Large | 85.22 |
| Connie Maxwell Children's HomeEIN 57-0324927 | Human Services | SC | $9,553,199Mid-sized | 87.85 |
| Conservancy for Cuyahoga Valley National ParkEIN 34-1917257 | Environment | OH | $4,242,928Mid-sized | 88.91 |
| 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 |
| Consortium for Graduate Study in ManagementEIN 43-0962198 | Education | MO | $36,743,080Large | 84.82 |
| Constitutional Rights FoundationEIN 95-2219680 | Education | CA | $1,944,718Small | 86.71 |
| Contemplative OutreachEIN 13-3345685 | Religion | NJ | $864,788Small | 80.86 |
| Contemporary Arts Center, CincinnatiEIN 31-0590095 | Arts, Culture, Humanities | OH | $4,498,292Mid-sized | 84.87 |
| Contemporary Arts Center, New OrleansEIN 72-0798830 | Arts, Culture, Humanities | LA | $3,623,733Mid-sized | 87.95 |
| Contemporary Arts Museum HoustonEIN 74-1093771 | Arts, Culture, Humanities | TX | $2,751,030Small | 83.77 |
| Convalescent Aid SocietyEIN 95-1782304 | Health | CA | $1,081,202Small | 88.51 |
| Cookie CartEIN 41-1866804 | Human Services | MN | $1,819,163Small | 86.99 |
| Cool GirlsEIN 58-1958246 | Human Services | GA | $557,843Small | 81.93 |
| Cornerstone Schools AssociationEIN 38-2995984 | Education | MI | $7,238,576Mid-sized | 82.97 |
| Cornerstone Theater CompanyEIN 95-4493498 | Arts, Culture, Humanities | CA | $1,289,866Small | 86.04 |
| Coro New York Leadership CenterEIN 13-3571610 | Education | NY | $2,587,498Small | 87.70 |
| Coro Northern CaliforniaEIN 94-3117758 | Education | CA | $1,502,444Small | 83.85 |
| Correctional Peace Officers FoundationEIN 68-0023302 | Human Services | CA | $8,090,088Mid-sized | 86.30 |
| COSI Center of Science and IndustryEIN 31-4383802 | Arts, Culture, Humanities | OH | $17,916,053Large | 85.79 |
| Council for Children's RightsEIN 56-1325184 | Human Services | NC | $2,443,075Small | 81.60 |
| Council for Educational ChangeEIN 01-0638224 | Education | FL | $2,174,131Small | 85.92 |
| Council for National PolicyEIN 72-0921017 | Research and Public Policy | DC | $2,680,790Small | 84.02 |
| Council of Independent CollegesEIN 01-6004776 | Education | DC | $13,706,554Large | 87.42 |
| Council on Foreign RelationsEIN 13-1628168 | International | NY | $69,262,800Large | 87.81 |
| Country Music FoundationEIN 62-0753887 | Arts, Culture, Humanities | TN | $31,719,231Large | 80.61 |
| Couple to Couple LeagueEIN 31-0842914 | Human and Civil Rights | OH | $1,615,421Small | 86.15 |
| Court Appointed Special Advocates of Orange CountyEIN 33-0069334 | Human Services | CA | $2,514,265Small | 87.81 |
| Covenant House MissouriEIN 43-1821599 | Human Services | MO | $3,540,058Mid-sized | 89.95 |
| Covenant House New YorkEIN 13-3076376 | Human Services | NY | $21,165,223Large | 88.04 |
| Coyote Hill Christian Children's HomeEIN 43-1601128 | Human Services | MO | $1,387,328Small | 83.99 |
| Cradle BeachEIN 16-0743025 | Human Services | NY | $2,496,471Small | 83.94 |
| Creative ActionEIN 74-2856925 | Human Services | TX | $3,712,943Mid-sized | 88.65 |
| Creative CommonsEIN 04-3585301 | Research and Public Policy | CA | $3,342,546Small | 89.05 |
| Creative TimeEIN 13-2835847 | Arts, Culture, Humanities | NY | $2,920,073Small | 86.13 |
| Crisis Assistance MinistryEIN 56-1416719 | Human Services | NC | $15,189,615Large | 89.39 |
| Crisis Control MinistryEIN 23-7348168 | Human Services | NC | $4,455,399Mid-sized | 89.39 |
| Crohn's & Colitis Foundation EIN 13-6193105 | Health | NY | $75,664,404Large | 88.16 |
| Crooked Tree Arts CenterEIN 23-7187264 | Arts, Culture, Humanities | MI | $2,194,400Small | 82.56 |
| CrossOver Healthcare MinistryEIN 54-1371067 | Health | VA | $5,840,704Mid-sized | 89.02 |
| Crossroads of MichiganEIN 38-2539852 | Human Services | MI | $1,325,518Small | 89.70 |
| Crosswinds Youth ServicesEIN 23-7376943 | Human Services | FL | $3,016,776Small | 87.25 |
| Crow Canyon Archaeological CenterEIN 84-0631786 | Arts, Culture, Humanities | CO | $4,488,765Mid-sized | 86.52 |
| Crown Point Community FoundationEIN 31-0247014 | Community Development | IN | $1,689,704Small | 83.83 |
| CSB MinistriesEIN 36-2472249 | Religion | NY | $740,300Small | 80.96 |
| Cultural Landscape FoundationEIN 52-2092229 | Environment | DC | $1,301,543Small | 86.63 |
| Cultural SurvivalEIN 23-7182593 | Human and Civil Rights | MA | $2,010,575Small | 88.27 |
| Cumberland Presbyterian Children's HomeEIN 75-0878543 | Human Services | TX | $2,798,013Small | 82.10 |
| Curamericas GlobalEIN 56-1400098 | International | NC | $1,138,062Small | 81.58 |
| Cure SMAEIN 36-3320440 | Health | IL | $7,566,017Mid-sized | 84.58 |
| CurePSPEIN 52-1704978 | Health | NY | $2,357,223Small | 80.65 |
| CuriOdysseyEIN 94-1262434 | Arts, Culture, Humanities | CA | $4,418,168Mid-sized | 86.57 |
| D-Rev Design for the Other Ninety PercentEIN 26-0642778 | Health | CA | $1,828,897Small | 88.06 |