| U.S. Dream AcademyEIN 59-3514841 | Human Services | MD | $2,573,866Small | 76.25 |
| U.S. PIRG Education FundEIN 52-1384240 | Human and Civil Rights | MA | $1,838,729Small | 72.89 |
| U.S. Ski and Snowboard Team FoundationEIN 84-6030639 | Human Services | UT | $12,608,521Mid-sized | 84.76 |
| U.S., Inc.EIN 38-2418377 | Research and Public Policy | MI | $1,838,596Small | 75.70 |
| UCP Wheels for HumanityEIN 95-4581144 | International | CA | $6,086,262Mid-sized | 88.31 |
| Uih Family PartnersEIN 21-0635048 | Human Services | NJ | $1,230,248Small | 79.97 |
| UJA Federation of GreenwichEIN 06-6068624 | Community Development | CT | $1,986,161Small | 84.08 |
| UJA-Federation of New YorkEIN 51-0172429 | Community Development | NY | $236,483,000Large | 89.47 |
| Ukrainian Catholic Education FoundationEIN 36-4126296 | Religion | IL | $5,822,751Mid-sized | 91.78 |
| ULI FoundationEIN 23-7133957 | Community Development | DC | $6,498,365Mid-sized | 90.36 |
| Umoja Student Development CorporationEIN 36-4263664 | Education | IL | $2,706,226Small | 92.18 |
| UnboundEIN 43-1243999 | International | KS | $128,095,891Large | 91.05 |
| UNCFEIN 13-1624241 | Education | DC | $171,722,769Large | 88.22 |
| Uncommon SchoolsEIN 31-1488698 | Education | NY | $42,868,589Large | 88.40 |
| UNICEF USAEIN 13-1760110 | International | NY | $512,770,720Large | 83.94 |
| UnidosUSEIN 86-0212873 | Human and Civil Rights | DC | $31,634,959Large | 90.28 |
| Union Gospel Mission of Grays HarborEIN 91-0580853 | Human Services | WA | $842,239Small | 82.79 |
| Union Gospel Mission of Tarrant CountyEIN 75-6054677 | Human Services | TX | $7,236,943Mid-sized | 89.77 |
| Union Gospel Mission Twin CitiesEIN 41-0705847 | Human Services | MN | $15,480,488Large | 85.46 |
| Union Gospel Mission, SacramentoEIN 94-6103618 | Human Services | CA | $3,824,237Mid-sized | 81.57 |
| Union League Boys & Girls ClubsEIN 36-2167939 | Human Services | IL | $5,382,975Mid-sized | 94.07 |
| Union MissionEIN 55-6000896 | Human Services | WV | $5,449,476Mid-sized | 76.91 |
| Union Mission MinistriesEIN 54-0506427 | Human Services | VA | $7,945,549Mid-sized | 87.63 |
| Union Rescue Mission, Little RockEIN 71-0348993 | Human Services | AR | $829,732Small | 74.89 |
| Union Rescue Mission, Los AngelesEIN 95-1709293 | Human Services | CA | $24,302,000Large | 87.47 |
| Union Station Homeless ServicesEIN 95-3958741 | Human Services | CA | $9,281,855Mid-sized | 95.60 |
| Unitarian Universalist Service CommitteeEIN 04-6186012 | International | MA | $9,534,499Mid-sized | 96.26 |
| United AbilityEIN 63-0307960 | Health | AL | $11,695,930Mid-sized | 95.29 |
| United American PatriotsEIN 41-2172043 | Human Services | VA | $3,422,626Small | 81.27 |
| United Arts Council of Greater GreensboroEIN 56-0746180 | Arts, Culture, Humanities | NC | $2,570,649Small | 83.64 |
| United Arts Council of Raleigh and Wake CountyEIN 56-0770175 | Arts, Culture, Humanities | NC | $1,453,428Small | 89.55 |
| United Arts of Central FloridaEIN 59-1166446 | Arts, Culture, Humanities | FL | $6,374,533Mid-sized | 87.36 |
| United Board for Christian Higher Education in AsiaEIN 13-5562367 | Religion | NY | $8,360,082Mid-sized | 84.42 |
| United Breast Cancer FoundationEIN 11-3571208 | Health | NY | $14,592,817Large | 73.72 |
| United Community Ministries (UCM of Alexandria)EIN 54-0850780 | Human Services | VA | $4,600,611Mid-sized | 83.84 |
| United Food BankEIN 86-0505273 | Human Services | AZ | $42,659,816Large | 89.95 |
| United Food Bank and Services of Plant CityEIN 59-3069728 | Human Services | FL | $3,768,609Mid-sized | 77.44 |
| United for a Fair EconomyEIN 04-3286118 | Research and Public Policy | MA | $965,479Small | 75.30 |
| United Friends of the ChildrenEIN 95-3665186 | Human Services | CA | $6,758,738Mid-sized | 91.79 |
| United Holy Land FundEIN 43-6100111 | International | IL | $2,147,491Small | 75.55 |
| United Hospice of RocklandEIN 13-3425315 | Human Services | NY | $7,838,564Mid-sized | 87.25 |
| United Hospital FundEIN 13-1562656 | Research and Public Policy | NY | $11,358,050Mid-sized | 83.89 |
| United Jewish Community of the Virginia PeninsulaEIN 54-0480621 | Human and Civil Rights | VA | $1,825,193Small | 80.57 |
| United Jewish Federation of Greater Stamford, New Canaan and DarienEIN 06-0923384 | Community Development | CT | $1,364,273Small | 78.11 |
| United Jewish Federation of Princeton Mercer BucksEIN 23-2215070 | Community Development | NJ | $926,565Small | 76.53 |
| United Methodist Children's HomeEIN 63-0302145 | Human Services | AL | $6,238,851Mid-sized | 89.59 |
| United Methodist Committee on ReliefEIN 13-5562279 | International | GA | $55,514,318Large | 92.14 |
| United Methodist Community HouseEIN 38-1360555 | Human Services | MI | $2,085,155Small | 80.42 |
| United Methodist Homes of New Jersey FoundationEIN 22-2720958 | Human Services | NJ | $924,523Small | 63.82 |
| United Methodist Open DoorEIN 48-0731995 | Human Services | KS | $2,885,655Small | 88.32 |
| United MinistriesEIN 57-0511977 | Human Services | SC | $2,020,464Small | 93.02 |
| United Mitochondrial Disease FoundationEIN 25-1767180 | Health | PA | $3,387,167Small | 78.81 |
| United Nations FoundationEIN 58-2368165 | International | DC | $116,848,010Large | 89.68 |
| United Palestinian AppealEIN 11-2494808 | International | DC | $23,225,518Large | 96.46 |
| United Performing Arts FundEIN 39-6100399 | Arts, Culture, Humanities | WI | $10,687,448Mid-sized | 92.92 |
| United Religions InitiativeEIN 68-0369482 | Religion | CA | $3,392,439Small | 92.44 |
| United States Capitol Historical SocietyEIN 52-0796820 | Arts, Culture, Humanities | DC | $2,148,017Small | 88.50 |
| United States Coast Guard Academy Alumni AssociationEIN 06-1354978 | Education | CT | $5,075,576Mid-sized | 86.53 |
| United States Equestrian Team FoundationEIN 22-1668879 | Human Services | NJ | $6,479,179Mid-sized | 86.58 |
| United States Golf AssociationEIN 13-1427105 | Human Services | NJ | $202,105,781Large | 87.52 |