| Morris Animal FoundationEIN 84-6032307 | Animals | CO | $10,893,273Mid-sized | 81.92 |
| Morris Habitat for HumanityEIN 22-2675802 | Community Development | NJ | $6,111,048Mid-sized | 92.92 |
| Morton Plant Mease FoundationEIN 59-1751535 | Health | FL | $9,663,293Mid-sized | 88.73 |
| MOSIEIN 59-2657399 | Arts, Culture, Humanities | FL | $6,806,453Mid-sized | 82.73 |
| mothers2mothersEIN 30-0545760 | International | CA | $4,284,671Mid-sized | 80.54 |
| Moultrie YMCAEIN 58-0593424 | Human Services | GA | $3,989,387Mid-sized | 85.15 |
| Mount Desert Island Biological LaboratoryEIN 01-0202467 | Research and Public Policy | ME | $11,741,518Mid-sized | 92.61 |
| Mount Sinai Medical Center FoundationEIN 59-1711400 | Health | FL | $5,220,734Mid-sized | 71.34 |
| Mountain Association for Community Economic DevelopmentEIN 31-0900246 | Community Development | KY | $5,071,264Mid-sized | 96.63 |
| Ms. Foundation for WomenEIN 23-7252609 | Human and Civil Rights | NY | $7,138,935Mid-sized | 79.00 |
| Muhammad Ali CenterEIN 61-1323046 | Arts, Culture, Humanities | KY | $5,711,406Mid-sized | 89.16 |
| Multidisciplinary Association for Psychedelic StudiesEIN 59-2751953 | Health | CA | $3,572,643Mid-sized | 84.13 |
| Multiple Sclerosis FoundationEIN 59-2792934 | Health | FL | $7,701,261Mid-sized | 75.54 |
| Museum of American FinanceEIN 13-3540880 | Arts, Culture, Humanities | NY | $4,447,277Mid-sized | 78.86 |
| Museum of Arts & DesignEIN 13-3585408 | Arts, Culture, Humanities | NY | $12,077,991Mid-sized | 83.32 |
| Museum of Arts & SciencesEIN 59-1022050 | Arts, Culture, Humanities | FL | $3,921,662Mid-sized | 89.39 |
| Museum of Contemporary Art DenverEIN 84-1366092 | Arts, Culture, Humanities | CO | $4,318,686Mid-sized | 83.66 |
| Museum of Contemporary Art San DiegoEIN 95-1855640 | Arts, Culture, Humanities | CA | $8,424,727Mid-sized | 82.72 |
| Museum of Discovery and ScienceEIN 59-1709542 | Arts, Culture, Humanities | FL | $9,225,857Mid-sized | 96.64 |
| Museum of GlassEIN 91-1669422 | Arts, Culture, Humanities | WA | $4,684,363Mid-sized | 86.45 |
| Museum of Latin American ArtEIN 33-0786070 | Arts, Culture, Humanities | CA | $3,997,352Mid-sized | 81.92 |
| Museum of New Mexico FoundationEIN 85-0202503 | Arts, Culture, Humanities | NM | $5,184,980Mid-sized | 93.44 |
| Museum of the Moving ImageEIN 11-2730714 | Arts, Culture, Humanities | NY | $6,904,332Mid-sized | 83.07 |
| Museum of the Shenandoah ValleyEIN 54-1857973 | Arts, Culture, Humanities | VA | $5,590,733Mid-sized | 96.74 |
| Music Academy of the WestEIN 95-1525814 | Education | CA | $10,929,662Mid-sized | 92.89 |
| Music Center FoundationEIN 23-7298290 | Arts, Culture, Humanities | CA | $7,702,956Mid-sized | 87.47 |
| Music Hall Center for the Performing ArtsEIN 38-2019397 | Arts, Culture, Humanities | MI | $5,438,374Mid-sized | 71.28 |
| Music Theatre of WichitaEIN 48-0785658 | Arts, Culture, Humanities | KS | $3,808,004Mid-sized | 88.46 |
| MusiCaresEIN 95-4470909 | Arts, Culture, Humanities | CA | $9,815,849Mid-sized | 91.73 |
| MUST MinistriesEIN 58-2034725 | Human Services | GA | $8,989,038Mid-sized | 94.33 |
| Mustard Seed CommunitiesEIN 58-1657207 | International | MA | $4,780,213Mid-sized | 98.23 |
| My Brother's KeeperEIN 04-3088412 | Human Services | MA | $4,044,691Mid-sized | 91.02 |
| myFaceEIN 13-6013760 | Health | NY | $3,618,719Mid-sized | 91.74 |
| N Street VillageEIN 52-1007373 | Human Services | DC | $7,693,664Mid-sized | 93.54 |
| Naismith Memorial Basketball Hall of FameEIN 04-6128892 | Arts, Culture, Humanities | MA | $10,289,678Mid-sized | 88.18 |
| NALEO Educational FundEIN 52-1212849 | Research and Public Policy | CA | $8,307,589Mid-sized | 86.84 |
| Nantucket Historical AssociationEIN 04-6003451 | Arts, Culture, Humanities | MA | $5,456,879Mid-sized | 84.34 |
| Naples Botanical GardenEIN 65-0511429 | Environment | FL | $8,405,351Mid-sized | 87.78 |
| NARAL Pro-Choice America FoundationEIN 52-1100361 | Human and Civil Rights | DC | $7,808,947Mid-sized | 96.66 |
| Nashville Public RadioEIN 62-1631652 | Arts, Culture, Humanities | TN | $4,962,835Mid-sized | 87.05 |
| Nashville Public TelevisionEIN 62-1740928 | Arts, Culture, Humanities | TN | $5,583,266Mid-sized | 87.37 |
| National Ability CenterEIN 94-3025807 | Human Services | UT | $6,238,931Mid-sized | 92.45 |
| National Abortion FederationEIN 43-1097957 | Human and Civil Rights | DC | $7,494,407Mid-sized | 96.66 |
| National Academy of Engineering FundEIN 23-7284092 | Research and Public Policy | DC | $9,369,619Mid-sized | 80.56 |
| National Action Council for Minorities in EngineeringEIN 52-1190664 | Education | NY | $4,207,670Mid-sized | 79.02 |
| National Alliance to End HomelessnessEIN 52-1299641 | Human Services | DC | $4,134,436Mid-sized | 91.42 |
| National Archives FoundationEIN 52-1792608 | Arts, Culture, Humanities | DC | $4,613,118Mid-sized | 80.67 |
| National Association of Charter School AuthorizersEIN 84-1553195 | Education | IL | $6,522,654Mid-sized | 85.00 |
| National Association of Chiefs of PoliceEIN 59-1164090 | Human Services | FL | $3,647,564Mid-sized | 77.64 |
| National AviaryEIN 25-1667146 | Animals | PA | $6,130,917Mid-sized | 90.73 |
| National Braille PressEIN 04-2104740 | Human Services | MA | $4,055,854Mid-sized | 79.76 |
| National Brain Tumor SocietyEIN 04-3068130 | Health | MA | $8,536,282Mid-sized | 77.82 |
| National Breast Cancer Foundation, Inc.EIN 75-2391148 | Health | TX | $12,307,503Mid-sized | 85.82 |
| National Building MuseumEIN 52-1050999 | Arts, Culture, Humanities | DC | $6,830,990Mid-sized | 80.74 |
| National Bureau of Asian ResearchEIN 91-1444105 | Research and Public Policy | WA | $5,395,449Mid-sized | 81.05 |
| National Center for Families LearningEIN 61-1159549 | Education | KY | $6,510,923Mid-sized | 90.52 |
| National Center for Learning DisabilitiesEIN 13-2899381 | Education | NY | $9,118,243Mid-sized | 95.47 |
| National Center for Lesbian RightsEIN 94-3086885 | Human and Civil Rights | CA | $4,861,287Mid-sized | 79.03 |
| National Center for Public Policy ResearchEIN 52-1226614 | Human and Civil Rights | DC | $4,829,357Mid-sized | 66.88 |
| National Center for Youth LawEIN 94-2506933 | Human and Civil Rights | CA | $6,884,801Mid-sized | 95.25 |