| Masonite NC | Manufacturing | 0 | - | F |
| Masonite TN | Manufacturing | 0 | - | D |
| Masonite Coorporation TX | - | 0 | - | - |
| Masonite Corporation FL | Manufacturing | 1 | $97,682 | A |
| Masonite Corporation KY | - | 0 | - | - |
| Masonite Corporation MO | - | 0 | - | - |
| Masonite Corporation NY | Wholesale Trade | 0 | - | F |
| Masonite Corporation OH | Wholesale Trade | 8 | $138,528 | D |
| Masonite Corporation PA | Manufacturing | 0 | - | F |
| Masonite Corporation VA | Wholesale Trade | 0 | - | B |
| Masonite Corporation (Greenville) TX | - | 0 | - | - |
| Masonite Corporations SC | - | 0 | - | - |
| Masonite International IN | Manufacturing | 0 | - | C |
| Masonite International TX | Manufacturing | 0 | - | D |
| Masonite International Corp WI | Manufacturing | 0 | - | F |
| Masonite International Corporation CA | Manufacturing | 0 | - | D |
| Masonomics, Inc. KY | Construction | 0 | - | F |
| Masoud Khorsand-Sahbaie, M.D., P.A. NM | - | 2 | $425,000 | - |
| Mass Audubon MA | Other Services | 0 | - | D |
| MASS Design Group, Ltd. MA | Professional & Technical Services | 3 | $70,000 | - |
| Mass Electric Construction Co NE | Construction | 3 | $98,540 | - |
| Mass General Brigham NH | Healthcare & Social Assistance | 0 | - | D |
| Mass General Brigham Health Plan MA | - | 4 | $151,227 | - |
| Mass General Brigham Incorporated MA | Healthcare & Social Assistance | 49 | $92,990 | F |
| Mass General Brigham Medical Group Northern Massachusetts MA | Healthcare & Social Assistance | 4 | $287,997 | - |
| Mass General Brigham Medical Group, NH & Maine, Inc NH | - | 4 | $420,625 | - |
| Mass Park Inc. d/b/a Valet Park of America CT | Other Services | 0 | - | F |
| Mass Park Inc. d/b/a Valet Park of America MA | Other Services | 0 | - | F |
| MASS Precision, Inc. CA | Manufacturing | 0 | - | F |
| Mass Transportation Authority MI | Transportation & Warehousing | 0 | - | B |
| Massa Multimedia Architecture PC NJ | Professional & Technical Services | 3 | - | - |
| Massac Memorial Hospital IL | Healthcare & Social Assistance | 0 | - | B |
| Massachusetts Acute Care Specialists, PC TN | Healthcare & Social Assistance | 2 | $253,760 | - |
| Massachusetts Association of Health Plans MA | Other Services | 1 | $110,000 | - |
| Massachusetts Bay Transportation Authority MA | Transportation & Warehousing | 1 | $116,735 | - |
| Massachusetts Convention Center Authority MA | Real Estate | 1 | $123,219 | - |
| Massachusetts Electric Co MA | Utilities | 0 | - | F |
| Massachusetts Eye and Ear Associates MA | Healthcare & Social Assistance | 6 | $83,158 | - |
| Massachusetts Eye and Ear Infirmary MA | Healthcare & Social Assistance | 31 | $73,798 | - |
| Massachusetts Financial Services Company MA | - | 1 | $114,015 | - |
| Massachusetts General Physicians Organization MA | Healthcare & Social Assistance | 54 | $118,458 | - |
| Massachusetts General Physicians Organization, Inc. (MGPO)/Massachusetts General Hospital (MGH) MA | Healthcare & Social Assistance | 3 | $416,529 | - |
| Massachusetts Institute of Technology MA | Educational Services | 219 | $80,784 | - |
| Massachusetts Medical Society MA | Other Services | 2 | $132,656 | - |
| Massachusetts Mutual Life Insurance Company MA | Finance & Insurance | 66 | $148,616 | - |
| Massachusetts Mutual Life Insurance Company NC | - | 0 | - | - |
| Massachusetts Mutual Life Insurance Company* CT | - | 0 | - | - |
| Massachusetts Port Authority MA | Transportation & Warehousing | 1 | $150,000 | - |
| Massage Envy AZ | - | 0 | - | - |
| Massage Envy RI | - | 0 | - | - |