| 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 Brothers Big Sisters of the MidlandsEIN 47-0466144 | Human Services | NE | $2,318,385Small | 91.49 |
| Big Brothers Big Sisters of the Sun CoastEIN 59-1361826 | Human Services | FL | $2,506,829Small | 88.12 |
| Big Brothers Big Sisters of the TriangleEIN 56-2109717 | Human Services | NC | $841,613Small | 86.38 |
| Big City MountaineersEIN 65-0200163 | Human Services | CO | $1,036,772Small | 87.09 |
| 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 Shoulders FundEIN 36-3490557 | Education | IL | $18,807,655Large | 98.64 |
| 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 |
| Bike & BuildEIN 36-4524531 | Community Development | PA | $1,117,167Small | 83.08 |
| Bike Works SeattleEIN 91-1753062 | Human Services | WA | $1,514,495Small | 90.62 |
| Bikes Not BombsEIN 04-3138753 | International | MA | $1,482,741Small | 86.84 |
| Bill Glass Behind the WallsEIN 75-2733954 | Religion | TX | $2,692,093Small | 95.08 |
| Bill of Rights InstituteEIN 48-0891418 | Education | VA | $3,151,238Small | 83.26 |
| Binghampton Christian AcademyEIN 62-1555775 | Education | TN | $1,396,779Small | 73.41 |
| Biomimicry InstituteEIN 86-1153859 | Environment | MT | $945,865Small | 80.43 |
| BioneersEIN 85-0432731 | Environment | NM | $4,165,702Mid-sized | 85.37 |
| Birch Community ServicesEIN 93-1186020 | Human Services | OR | $15,057,816Large | 92.24 |
| Bird Street Community CenterEIN 04-2708670 | Human Services | MA | $1,635,684Small | 80.05 |
| Birmingham ZooEIN 62-1231591 | Animals | AL | $11,471,890Mid-sized | 93.98 |
| Birthright Israel FoundationEIN 13-4092050 | Education | NY | $98,592,432Large | 90.74 |
| Bishop MuseumEIN 99-0161980 | Arts, Culture, Humanities | HI | $13,420,724Mid-sized | 76.66 |
| Bishop Sullivan CenterEIN 43-1750848 | Human Services | MO | $1,726,054Small | 84.68 |
| Bivona Child Advocacy CenterEIN 03-0519569 | Human Services | NY | $1,571,580Small | 94.34 |
| Black AIDS InstituteEIN 95-4742741 | Health | CA | $2,147,395Small | 88.86 |
| Black Mountain Home for Children, Youth & FamiliesEIN 56-0538018 | Human Services | NC | $3,825,147Mid-sized | 93.89 |
| Black Student FundEIN 52-6053597 | Education | DC | $407,911Small | 64.72 |
| Bladder Cancer Advocacy NetworkEIN 20-2897110 | Health | MD | $2,104,302Small | 94.88 |
| Blandford Nature CenterEIN 20-0739420 | Environment | MI | $1,358,816Small | 85.35 |
| Blank Park ZooEIN 42-1171821 | Animals | IA | $7,017,106Mid-sized | 88.24 |
| BLESS USAEIN 13-3602362 | International | NJ | $1,205,470Small | 65.86 |
| Blessed Family Association InternationalEIN 20-5717831 | Human Services | WA | $1,109,782Small | 64.72 |
| 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 |
| Blind Children's Learning CenterEIN 95-6097023 | Education | CA | $2,816,982Small | 94.51 |
| BlinkNow FoundationEIN 26-0819262 | International | NJ | $2,388,119Small | 97.84 |
| BlithewoldEIN 05-0503407 | Arts, Culture, Humanities | RI | $1,694,452Small | 89.34 |
| Blood:WaterEIN 56-2483082 | International | TN | $2,239,685Small | 76.38 |
| Blue Mountain Humane SocietyEIN 91-0828499 | Animals | WA | $1,066,237Small | 96.82 |
| Blue Ridge Area Food BankEIN 52-1202644 | Human Services | VA | $47,554,040Large | 94.26 |
| Blue Ridge ConservancyEIN 58-2502695 | Environment | NC | $5,516,928Mid-sized | 100.00 |
| Blue Ridge Public RadioEIN 58-1445328 | Arts, Culture, Humanities | NC | $2,365,620Small | 88.06 |
| Blue Ridge Public TelevisionEIN 54-0798878 | Arts, Culture, Humanities | VA | $3,330,734Small | 79.23 |
| 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 |
| BLUEBARN TheatreEIN 47-0742394 | Arts, Culture, Humanities | NE | $718,171Small | 83.20 |
| 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 |
| Bo's PlaceEIN 76-0326979 | Human Services | TX | $2,031,638Small | 91.94 |
| Boat US FoundationEIN 54-1156448 | Education | MD | $1,857,107Small | 74.78 |
| 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 |
| Boch CenterEIN 51-0197209 | Arts, Culture, Humanities | MA | $33,264,866Large | 91.98 |
| Bolder OptionsEIN 41-1909408 | Human Services | MN | $1,005,288Small | 81.41 |
| 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 |