| Martha's Village and KitchenEIN 33-0777892 | Human Services | CA | $3,578,914Mid-sized | 71.26 |
| Martha's Vineyard MuseumEIN 04-2160642 | Arts, Culture, Humanities | MA | $2,030,611Small | 73.37 |
| MarwenEIN 36-3523622 | Education | IL | $2,669,179Small | 86.93 |
| Mary's CenterEIN 52-1594116 | Human Services | DC | $46,327,345Large | 93.76 |
| Maryland Food BankEIN 52-1135690 | Human Services | MD | $68,947,210Large | 82.13 |
| Maryland Historical SocietyEIN 52-0403670 | Arts, Culture, Humanities | MD | $3,479,411Small | 84.20 |
| Maryland Science CenterEIN 52-0668166 | Arts, Culture, Humanities | MD | $8,419,673Mid-sized | 82.58 |
| Maryland Therapeutic RidingEIN 52-2035698 | Health | MD | $988,423Small | 80.56 |
| MasbiaEIN 20-1923521 | Human Services | NY | $1,581,255Small | 67.39 |
| Masonic Home for Children at OxfordEIN 56-0603924 | Human Services | NC | $5,835,714Mid-sized | 83.95 |
| Masonic Home of GeorgiaEIN 58-0140568 | Human Services | GA | $1,970,070Small | 87.50 |
| Masonic Homes of CaliforniaEIN 94-1156564 | Human Services | CA | $63,193,734Large | 91.49 |
| Masonic Medical Research LaboratoryEIN 13-5648611 | Health | NY | $3,253,665Small | 79.52 |
| Mass Mentoring PartnershipEIN 22-3207958 | Human Services | MA | $2,420,195Small | 87.97 |
| MASS MoCAEIN 04-3113688 | Arts, Culture, Humanities | MA | $14,296,459Large | 79.41 |
| Massachusetts Audubon SocietyEIN 04-2104702 | Environment | MA | $29,467,469Large | 95.33 |
| Massachusetts Coalition for the HomelessEIN 22-2599662 | Human Services | MA | $3,788,528Mid-sized | 91.02 |
| Massachusetts Down Syndrome CongressEIN 22-2596246 | Health | MA | $1,509,177Small | 89.75 |
| Massachusetts Horticultural SocietyEIN 04-2104714 | Environment | MA | $1,690,583Small | 83.57 |
| Massachusetts Immigrant and Refugee Advocacy CoalitionEIN 22-3115048 | Human and Civil Rights | MA | $1,949,092Small | 86.25 |
| Massanetta SpringsEIN 54-0505926 | Religion | VA | $1,173,464Small | 74.84 |
| MassBioEdEIN 22-3799632 | Education | MA | $1,302,935Small | 87.92 |
| MassINCEIN 04-3271457 | Research and Public Policy | MA | $1,950,185Small | 83.15 |
| Mastermedia InternationalEIN 33-0104548 | Religion | CA | $1,427,531Small | 70.76 |
| MasterVoicesEIN 13-1606158 | Arts, Culture, Humanities | NY | $1,780,240Small | 86.08 |
| MATHCOUNTSEIN 54-1295407 | Education | VA | $2,746,171Small | 89.42 |
| Matt Talbot Kitchen & OutreachEIN 36-3945814 | Human Services | NE | $1,804,330Small | 91.39 |
| Mattatuck MuseumEIN 06-0443990 | Arts, Culture, Humanities | CT | $2,420,763Small | 84.18 |
| MATTEREIN 37-1441658 | International | MN | $23,343,824Large | 93.23 |
| Matthew 25: MinistriesEIN 31-1348100 | International | OH | $210,847,427Large | 100.00 |
| Mattress FactoryEIN 25-1338941 | Arts, Culture, Humanities | PA | $2,030,527Small | 87.88 |
| Maui Arts & Cultural CenterEIN 99-0222998 | Arts, Culture, Humanities | HI | $11,032,907Mid-sized | 78.21 |
| Maui Food BankEIN 99-0315110 | Human Services | HI | $5,796,262Mid-sized | 97.58 |
| Maumee Valley Habitat for HumanityEIN 34-1584728 | Community Development | OH | $2,022,081Small | 96.22 |
| MaxFundEIN 84-1116882 | Animals | CO | $2,789,821Small | 93.74 |
| May Dugan CenterEIN 23-7061949 | Human Services | OH | $2,213,538Small | 90.94 |
| May FestivalEIN 31-0584309 | Arts, Culture, Humanities | OH | $2,682,723Small | 89.17 |
| Maymont FoundationEIN 54-6039788 | Arts, Culture, Humanities | VA | $5,202,382Mid-sized | 88.85 |
| Mayor's Alliance for NYC's AnimalsEIN 73-1653635 | Animals | NY | $1,632,234Small | 76.21 |
| Mayor's Fund to Advance New York CityEIN 13-3783906 | Community Development | NY | $22,870,687Large | 87.30 |
| MAZON: A Jewish Response to HungerEIN 22-2624532 | Human and Civil Rights | CA | $6,837,288Mid-sized | 88.88 |
| MA‘O Organic FarmsEIN 99-0350803 | Education | HI | $1,580,098Small | 83.01 |
| MCC TheaterEIN 13-3391844 | Arts, Culture, Humanities | NY | $5,134,774Mid-sized | 86.29 |
| McCallum TheatreEIN 95-2834871 | Arts, Culture, Humanities | CA | $13,663,160Large | 87.50 |
| McCarter Theatre Center for the Performing ArtsEIN 21-0724198 | Arts, Culture, Humanities | NJ | $12,663,474Mid-sized | 94.20 |
| McColl Center for Art + InnovationEIN 51-0195015 | Arts, Culture, Humanities | NC | $1,899,053Small | 81.20 |
| McKee Botanical GardenEIN 65-1189895 | Environment | FL | $1,443,755Small | 81.60 |
| McLaughlin Research Institute for Biomedical SciencesEIN 81-0459235 | Health | MT | $2,615,523Small | 87.14 |
| McLean County Museum of HistoryEIN 37-1414038 | Arts, Culture, Humanities | IL | $1,226,621Small | 84.49 |
| McNay Art MuseumEIN 74-1195277 | Arts, Culture, Humanities | TX | $9,680,975Mid-sized | 91.45 |
| McWane Science CenterEIN 58-1933712 | Arts, Culture, Humanities | AL | $6,970,316Mid-sized | 87.33 |
| MDS FoundationEIN 22-3283911 | Health | NJ | $3,321,416Small | 88.22 |
| Meals On Wheels AmericaEIN 23-7447812 | Human Services | VA | $13,443,686Mid-sized | 94.84 |
| Meals on Wheels Central TexasEIN 23-7202594 | Human Services | TX | $12,220,703Mid-sized | 92.61 |
| Meals on Wheels Diablo RegionEIN 68-0044205 | Human Services | CA | $2,114,669Small | 94.69 |
| Meals on Wheels of Contra CostaEIN 68-0231350 | Human Services | CA | $1,624,164Small | 84.42 |
| Meals on Wheels of GreenvilleEIN 57-0531378 | Human Services | SC | $1,871,108Small | 84.92 |
| Meals on Wheels of Johnson & Ellis CountiesEIN 75-1555153 | Human Services | TX | $2,548,467Small | 82.16 |
| Meals On Wheels of San FranciscoEIN 94-1741155 | Human Services | CA | $12,626,188Mid-sized | 90.34 |
| Meals on Wheels of TampaEIN 59-1679915 | Human Services | FL | $2,372,731Small | 93.57 |