| Humane Society of Huron ValleyEIN 38-1474931 | Animals | MI | $6,103,506Mid-sized | 93.85 |
| Humane Society of IndianapolisEIN 35-0876385 | Animals | IN | $7,172,643Mid-sized | 94.27 |
| Humane Society of Manatee CountyEIN 59-1819652 | Animals | FL | $2,076,144Small | 98.10 |
| Humane Society of MissouriEIN 43-0652638 | Animals | MO | $19,333,513Large | 91.59 |
| Humane Society of New YorkEIN 13-1624041 | Animals | NY | $5,438,620Mid-sized | 93.44 |
| Humane Society of North TexasEIN 75-1245911 | Animals | TX | $5,780,539Mid-sized | 94.34 |
| Humane Society of Pulaski CountyEIN 71-0415296 | Animals | AR | $1,084,913Small | 92.92 |
| Humane Society of Sarasota CountyEIN 59-6014943 | Animals | FL | $2,670,729Small | 100.00 |
| Humane Society of Sonoma CountyEIN 94-6001315 | Animals | CA | $4,599,091Mid-sized | 90.62 |
| Humane Society of South Coastal GeorgiaEIN 58-6073265 | Animals | GA | $826,631Small | 90.71 |
| Humane Society of the Pikes Peak RegionEIN 84-0410111 | Animals | CO | $11,979,958Mid-sized | 94.39 |
| Humane Society of the Treasure CoastEIN 59-0774235 | Animals | FL | $3,129,574Small | 90.29 |
| Humane Society of UtahEIN 87-0256350 | Animals | UT | $5,664,922Mid-sized | 91.77 |
| Humble Area Assistance MinistriesEIN 76-0298820 | Human Services | TX | $5,759,866Mid-sized | 96.46 |
| Huntington's Disease Society of AmericaEIN 13-3349872 | Health | NY | $8,627,132Mid-sized | 92.78 |
| Huron River Watershed CouncilEIN 38-1806452 | Environment | MI | $1,487,897Small | 94.06 |
| Hyde Park Art CenterEIN 36-2887294 | Arts, Culture, Humanities | IL | $2,226,933Small | 91.02 |
| I Know I CanEIN 31-1229135 | Education | OH | $4,477,894Mid-sized | 98.05 |
| Ibis Reproductive HealthEIN 03-0382773 | International | MA | $7,438,558Mid-sized | 91.51 |
| ICM Food & Clothing BankEIN 86-0401223 | Human Services | AZ | $6,612,702Mid-sized | 94.28 |
| ICNA Relief USAEIN 04-3810161 | Human Services | NY | $14,885,429Large | 95.47 |
| Idaho Conservation LeagueEIN 82-6042478 | Environment | ID | $1,970,384Small | 91.68 |
| Idaho FoodbankEIN 82-0425400 | Human Services | ID | $35,648,299Large | 93.48 |
| Idaho Humane SocietyEIN 82-0212536 | Animals | ID | $5,914,266Mid-sized | 96.18 |
| Idaho Youth RanchEIN 82-0253346 | Human Services | ID | $23,775,946Large | 91.16 |
| Illinois Network of Charter SchoolsEIN 14-1862409 | Education | IL | $2,793,417Small | 90.60 |
| Imagine Children's MuseumEIN 94-3153591 | Arts, Culture, Humanities | WA | $2,018,647Small | 96.07 |
| iMentorEIN 30-0105507 | Education | NY | $18,667,266Large | 90.00 |
| Immaculate Heart CommunityEIN 95-2706764 | Religion | CA | $6,222,928Mid-sized | 90.86 |
| Immigrant Law Center of MinnesotaEIN 41-0909036 | Human and Civil Rights | MN | $2,052,064Small | 95.32 |
| Immigrant Legal Resource CenterEIN 94-2939540 | Human and Civil Rights | CA | $11,365,899Mid-sized | 92.02 |
| Immokalee Child Care CenterEIN 59-1209842 | Human Services | FL | $1,322,503Small | 91.40 |
| Immune Deficiency FoundationEIN 52-1214782 | Health | MD | $8,349,918Mid-sized | 97.17 |
| Impression 5 Science CenterEIN 23-7200548 | Arts, Culture, Humanities | MI | $1,619,983Small | 90.58 |
| INCLUDEnycEIN 11-2594790 | Human Services | NY | $2,915,236Small | 92.80 |
| Independence InstituteEIN 84-0990300 | Research and Public Policy | CO | $2,907,995Small | 91.15 |
| Independent Catholic Foundation for the Diocese of Altoona-JohnstownEIN 25-1625390 | Religion | PA | $1,123,592Small | 96.69 |
| India Development and Relief Fund, Inc. (IDRF)EIN 52-1555563 | International | MD | $1,974,078Small | 98.23 |
| India Gospel League, North AmericaEIN 31-1423556 | Religion | OH | $3,563,796Mid-sized | 93.77 |
| Indian Law Resource CenterEIN 52-1121079 | Human and Civil Rights | MT | $1,268,568Small | 92.29 |
| Indian Muslim Relief and CharitiesEIN 27-0058132 | International | CA | $5,886,673Mid-sized | 94.74 |
| Indian River Habitat for HumanityEIN 65-0230079 | Community Development | FL | $5,733,247Mid-sized | 92.16 |
| Infant Crisis ServicesEIN 73-1378766 | Human Services | OK | $3,345,296Small | 92.89 |
| Infant Welfare Society of ChicagoEIN 36-2167752 | Health | IL | $9,544,302Mid-sized | 90.93 |
| Initiative for A Competitive Inner CityEIN 13-3772904 | Community Development | MA | $4,348,578Mid-sized | 97.05 |
| Initiative FoundationEIN 36-3451562 | Community Development | MN | $7,323,711Mid-sized | 92.11 |
| Inland Empire United WayEIN 33-0502676 | Community Development | CA | $6,839,548Mid-sized | 97.87 |
| INMED Partnerships for ChildrenEIN 52-1482339 | International | VA | $11,283,378Mid-sized | 95.04 |
| Inner City Law CenterEIN 95-3697572 | Human and Civil Rights | CA | $4,036,319Mid-sized | 93.16 |
| Inner-City ArtsEIN 95-4239478 | Education | CA | $3,939,718Mid-sized | 90.71 |
| INSIGHTEIN 05-0272278 | Human Services | RI | $848,297Small | 94.37 |
| Institute for Creation ResearchEIN 95-3523177 | Religion | TX | $7,585,130Mid-sized | 93.85 |
| Institute for Free SpeechEIN 20-3676886 | Human and Civil Rights | VA | $1,939,035Small | 97.23 |
| Institute for JusticeEIN 52-1744337 | Human and Civil Rights | VA | $22,312,263Large | 97.70 |
| 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 on Taxation and Economic PolicyEIN 04-2688165 | Research and Public Policy | DC | $1,804,899Small | 93.91 |
| Inter-Faith Council for Social ServiceEIN 59-1224041 | Human Services | NC | $2,451,180Small | 90.92 |
| InterActionEIN 13-3287064 | International | DC | $9,733,199Mid-sized | 91.01 |
| Intercollegiate Studies InstituteEIN 23-6050131 | Education | DE | $7,276,782Mid-sized | 94.89 |