| International Relief TeamsEIN 33-0412751 | International | CA | $38,184,357Large | 95.58 |
| International Rescue CommitteeEIN 13-5660870 | International | NY | $694,099,188Large | 91.16 |
| International Rett Syndrome FoundationEIN 31-1682518 | Health | OH | $5,001,314Mid-sized | 91.42 |
| International Rhino FoundationEIN 75-2395006 | Animals | TX | $2,814,196Small | 93.96 |
| International RiversEIN 94-3158295 | Environment | CA | $2,122,078Small | 82.97 |
| International SamaritanEIN 34-1811907 | International | MI | $2,056,011Small | 90.09 |
| International Senior Lawyers CorporationEIN 52-2241212 | Human and Civil Rights | NY | $1,291,304Small | 82.82 |
| International Society for Infectious DiseasesEIN 22-2473000 | Health | MA | $2,177,843Small | 87.68 |
| International Tennis Hall of FameEIN 13-6144356 | Arts, Culture, Humanities | RI | $10,386,956Mid-sized | 85.30 |
| International Waldenstrom's Macroglobulinemia FoundationEIN 54-1784426 | Health | FL | $2,762,604Small | 95.29 |
| International Wolf CenterEIN 41-1543539 | Animals | MN | $1,624,232Small | 95.22 |
| International Women's Health CoalitionEIN 23-7378153 | International | NY | $6,565,003Mid-sized | 94.76 |
| International Youth FoundationEIN 38-2935397 | International | MD | $22,195,791Large | 90.04 |
| Intersection for the ArtsEIN 94-1593216 | Arts, Culture, Humanities | CA | $3,286,407Small | 95.00 |
| InterServe USAEIN 23-1644377 | Religion | PA | $6,078,115Mid-sized | 85.85 |
| Interstitial Cystitis AssociationEIN 13-3292137 | Health | VA | $766,632Small | 78.96 |
| InterVarsity Christian Fellowship/USAEIN 36-2171714 | Religion | WI | $101,308,282Large | 90.91 |
| Intiman TheatreEIN 23-7328597 | Arts, Culture, Humanities | WA | $970,982Small | 76.76 |
| Intrepid Museum FoundationEIN 13-3062419 | Arts, Culture, Humanities | NY | $35,136,930Large | 87.01 |
| Invest in KidsEIN 84-1455282 | Human Services | CO | $2,449,872Small | 82.39 |
| Investigative Reporters & EditorsEIN 51-0166741 | Education | MO | $2,500,441Small | 91.67 |
| Invisible ChildrenEIN 54-2164338 | International | DC | $1,622,588Small | 79.04 |
| Iona Senior ServicesEIN 52-1039553 | Human Services | DC | $4,589,586Mid-sized | 94.78 |
| Iowa Citizens for Community ImprovementEIN 42-1110721 | Research and Public Policy | IA | $1,101,924Small | 88.90 |
| Iowa Sports FoundationEIN 42-1278326 | Human Services | IA | $1,750,215Small | 74.24 |
| Iowa State University Alumni AssociationEIN 42-6062614 | Education | IA | $4,416,820Mid-sized | 86.24 |
| IpasEIN 56-1071085 | Human and Civil Rights | NC | $63,318,776Large | 91.61 |
| Iran Alive MinistriesEIN 14-1865897 | Religion | TX | $1,585,923Small | 79.73 |
| Iranian American Jewish Federation of New YorkEIN 01-0651843 | Community Development | NY | $4,104,978Mid-sized | 98.23 |
| Iraq and Afghanistan Veterans of AmericaEIN 20-1664531 | Human and Civil Rights | NY | $7,230,821Mid-sized | 79.98 |
| Irish Arts CenterEIN 51-0244834 | Arts, Culture, Humanities | NY | $3,362,693Small | 81.56 |
| Irish Cultural CenterEIN 86-0930096 | Arts, Culture, Humanities | AZ | $859,521Small | 70.77 |
| Irish International Immigrant CenterEIN 04-3063382 | Human Services | MA | $1,920,895Small | 95.61 |
| Irvine Nature CenterEIN 52-1231286 | Environment | MD | $1,926,838Small | 90.75 |
| Irving CaresEIN 75-1436937 | Human Services | TX | $1,778,752Small | 85.87 |
| Isabella Stewart Gardner MuseumEIN 04-2104334 | Arts, Culture, Humanities | MA | $22,135,619Large | 88.13 |
| ISAIAHEIN 41-1957358 | Human and Civil Rights | MN | $2,585,091Small | 84.70 |
| Islamic Relief USAEIN 95-4453134 | International | VA | $150,398,532Large | 91.16 |
| Island HarvestEIN 11-3136350 | Human Services | NY | $20,780,134Large | 91.09 |
| Island InstituteEIN 22-2786731 | Community Development | ME | $5,392,897Mid-sized | 78.89 |
| Island PressEIN 94-2578166 | Environment | DC | $4,526,796Mid-sized | 89.27 |
| IslandWoodEIN 31-1654076 | Education | WA | $9,854,727Mid-sized | 90.56 |
| Israel Cancer Association USAEIN 13-6218184 | Health | FL | $826,326Small | 96.66 |
| Israel Cancer Research FundEIN 51-0181215 | Health | NY | $4,379,201Mid-sized | 80.22 |
| Israel Guide Dog Center for the BlindEIN 23-2519029 | Animals | PA | $3,959,395Mid-sized | 100.00 |
| Israel Scholarship Education FoundationEIN 13-2909403 | Education | NY | $1,579,306Small | 76.50 |
| Israel Tennis Centers Foundation EIN 13-2961273 | Human Services | NY | $5,681,128Mid-sized | 87.01 |
| Issaquah Schools FoundationEIN 94-3050254 | Education | WA | $1,780,418Small | 86.14 |
| It's The Journey, Inc.EIN 47-0897591 | Health | GA | $1,675,912Small | 92.27 |
| Izaak Walton League of AmericaEIN 36-1930035 | Environment | MD | $2,407,893Small | 85.81 |
| J Street Education FundEIN 20-2777557 | International | DC | $6,029,203Mid-sized | 86.45 |
| J103EIN 62-1535834 | Religion | TN | $2,317,625Small | 75.19 |
| Jack & Jill Children's CenterEIN 59-0637870 | Human Services | FL | $3,014,708Small | 88.30 |
| Jack and Jill Late Stage Cancer FoundationEIN 20-4415512 | Health | GA | $957,055Small | 88.74 |
| Jack Van Impe Ministries InternationalEIN 38-1956052 | Religion | MI | $5,902,713Mid-sized | 65.23 |
| Jackie Robinson FoundationEIN 13-2896345 | Education | NY | $8,797,164Mid-sized | 86.86 |
| Jackson Hole Conservation AllianceEIN 83-0245647 | Environment | WY | $720,418Small | 86.39 |
| Jacksonville Humane SocietyEIN 59-0624410 | Animals | FL | $4,140,723Mid-sized | 87.54 |
| Jacksonville Public Education FundEIN 59-2756660 | Education | FL | $2,224,299Small | 91.64 |
| Jacksonville Symphony OrchestraEIN 59-6002520 | Arts, Culture, Humanities | FL | $13,394,954Mid-sized | 87.57 |