| Benjamin Rose Institute on AgingEIN 34-0714482 | Human Services | OH | $11,049,876Mid-sized | 80.90 |
| Bet TzedekEIN 23-7304205 | Human and Civil Rights | CA | $7,647,552Mid-sized | 88.25 |
| Bethesda AcademyEIN 58-0637013 | Education | GA | $3,955,168Mid-sized | 86.29 |
| Bethesda MissionEIN 23-1389397 | Human Services | PA | $7,449,308Mid-sized | 90.71 |
| Better World FundEIN 58-2366765 | International | DC | $5,346,277Mid-sized | 78.51 |
| Beyond HousingEIN 51-0179471 | Community Development | MO | $10,959,490Mid-sized | 92.20 |
| Bible Broadcasting NetworkEIN 54-0888863 | Religion | NC | $11,664,277Mid-sized | 70.81 |
| BideaweeEIN 13-1655210 | Animals | NY | $10,621,175Mid-sized | 83.88 |
| Big Brothers Big Sisters Independence RegionEIN 23-1352034 | Human Services | PA | $6,865,078Mid-sized | 90.26 |
| Big Brothers Big Sisters Lone StarEIN 75-0800632 | Human Services | TX | $10,736,073Mid-sized | 76.67 |
| Big Brothers Big Sisters of Eastern MissouriEIN 43-0669085 | Human Services | MO | $4,922,339Mid-sized | 89.66 |
| Big Brothers Big Sisters of Greater Kansas CityEIN 43-6068464 | Human Services | MO | $3,900,296Mid-sized | 82.72 |
| Big Brothers Big Sisters of Greater Los AngelesEIN 95-1904857 | Human Services | CA | $3,769,785Mid-sized | 86.66 |
| Big Brothers Big Sisters of Massachusetts BayEIN 04-2074462 | Human Services | MA | $6,894,306Mid-sized | 91.06 |
| Big Brothers Big Sisters of Metro AtlantaEIN 58-0861895 | Human Services | GA | $4,054,562Mid-sized | 88.87 |
| Big Brothers Big Sisters of Metropolitan ChicagoEIN 36-2681212 | Human Services | IL | $4,638,926Mid-sized | 90.64 |
| Big Brothers Big Sisters of MiamiEIN 59-6166904 | Human Services | FL | $4,912,755Mid-sized | 91.93 |
| Big Brothers Big Sisters of New York CityEIN 13-5600383 | Human Services | NY | $10,979,467Mid-sized | 88.90 |
| Big Brothers Big Sisters of Orange CountyEIN 95-1992702 | Human Services | CA | $5,321,640Mid-sized | 91.77 |
| Big Brothers Big Sisters of Tampa BayEIN 59-2173085 | Human Services | FL | $4,990,990Mid-sized | 88.09 |
| Big Brothers Big Sisters of the Greater Twin CitiesEIN 32-0017737 | Human Services | MN | $5,810,205Mid-sized | 80.30 |
| Big Green Scholarship FoundationEIN 55-0631935 | Education | WV | $3,736,494Mid-sized | 82.14 |
| Big Oak RanchEIN 23-7413017 | Human Services | AL | $8,513,520Mid-sized | 94.90 |
| Big ThoughtEIN 75-2170035 | Education | TX | $7,097,230Mid-sized | 83.62 |
| Bigelow Laboratory for Ocean SciencesEIN 01-6006001 | Research and Public Policy | ME | $12,705,375Mid-sized | 96.66 |
| BioneersEIN 85-0432731 | Environment | NM | $4,165,702Mid-sized | 85.37 |
| Birmingham ZooEIN 62-1231591 | Animals | AL | $11,471,890Mid-sized | 93.98 |
| Bishop MuseumEIN 99-0161980 | Arts, Culture, Humanities | HI | $13,420,724Mid-sized | 76.66 |
| Black Mountain Home for Children, Youth & FamiliesEIN 56-0538018 | Human Services | NC | $3,825,147Mid-sized | 93.89 |
| Blank Park ZooEIN 42-1171821 | Animals | IA | $7,017,106Mid-sized | 88.24 |
| Blessings in A BackpackEIN 26-1964620 | Human Services | KY | $9,541,649Mid-sized | 92.20 |
| Blind and Vision Rehabilitation Services of PittsburghEIN 25-1803195 | Health | PA | $5,321,810Mid-sized | 78.44 |
| Blind Children's CenterEIN 95-1656369 | Human Services | CA | $3,528,570Mid-sized | 94.26 |
| Blue Ridge ConservancyEIN 58-2502695 | Environment | NC | $5,516,928Mid-sized | 100.00 |
| Blue Star FamiliesEIN 80-0369895 | Human Services | CA | $4,060,299Mid-sized | 95.13 |
| Blue Water BaltimoreEIN 52-1420138 | Environment | MD | $3,712,321Mid-sized | 89.35 |
| Bluegreen Alliance FoundationEIN 20-3477309 | Environment | MN | $3,883,863Mid-sized | 88.93 |
| Bnai Zion FoundationEIN 13-2572288 | International | NY | $4,004,928Mid-sized | 95.79 |
| Boca Helping HandsEIN 31-1713631 | Human Services | FL | $5,988,542Mid-sized | 93.11 |
| Boca Raton Museum of ArtEIN 59-6019851 | Arts, Culture, Humanities | FL | $5,574,318Mid-sized | 85.90 |
| Bonei OlamEIN 11-3473757 | Health | NY | $9,800,311Mid-sized | 85.03 |
| Bonnie J. Addario Lung Cancer FoundationEIN 20-4417327 | Health | CA | $4,708,201Mid-sized | 94.42 |
| Book TrustEIN 20-4124164 | Education | CO | $4,309,861Mid-sized | 89.78 |
| Boreal Songbird InitiativeEIN 91-2158784 | Animals | WA | $3,500,164Mid-sized | 76.59 |
| Boston AthenæumEIN 04-2104852 | Arts, Culture, Humanities | MA | $7,978,842Mid-sized | 87.70 |
| Boston Children's MuseumEIN 04-2103993 | Arts, Culture, Humanities | MA | $10,009,528Mid-sized | 89.89 |
| Boston Chinatown Neighborhood CenterEIN 23-7209691 | Human Services | MA | $5,315,258Mid-sized | 94.22 |
| Boston Latin School AssociationEIN 04-6035973 | Education | MA | $5,178,794Mid-sized | 87.24 |
| Boston Lyric OperaEIN 04-2469627 | Arts, Culture, Humanities | MA | $7,961,986Mid-sized | 88.03 |
| Botanical Research Institute of TexasEIN 75-2198196 | Research and Public Policy | TX | $5,266,139Mid-sized | 85.94 |
| Bottom LineEIN 04-3351427 | Education | MA | $11,646,639Mid-sized | 91.49 |
| Boulder Jewish Community CenterEIN 84-1322996 | Human Services | CO | $4,675,737Mid-sized | 92.19 |
| Bowers MuseumEIN 33-0106161 | Arts, Culture, Humanities | CA | $5,365,378Mid-sized | 82.15 |
| Boy Scouts of AmericaEIN 25-0965214 | Human Services | PA | $6,991,409Mid-sized | 89.18 |
| Boy Scouts of America Greater Cleveland CouncilEIN 34-0714322 | Human Services | OH | $3,627,058Mid-sized | 88.23 |
| Boy Scouts of America, Alamo Area CouncilEIN 74-6079583 | Human Services | TX | $4,811,177Mid-sized | 87.10 |
| Boy Scouts of America, Atlanta Area CouncilEIN 58-0566122 | Human Services | GA | $12,466,178Mid-sized | 90.69 |
| Boy Scouts of America, Capitol Area CouncilEIN 74-1143057 | Human Services | TX | $6,866,572Mid-sized | 94.03 |
| Boy Scouts of America, Cascade Pacific CouncilEIN 93-0386792 | Human Services | OR | $7,650,867Mid-sized | 78.05 |
| Boy Scouts of America, Central Florida CouncilEIN 59-0624376 | Human Services | FL | $7,280,233Mid-sized | 89.31 |