| 48501 | Massachusetts Convention Center Authority | 1 | $123,219 | 1 |
| 48502 | Massachusetts Financial Services Company | 1 | $158,148 | 1 |
| 48503 | Massachusetts Peace Action Education Fund | 1 | $69,992 | 1 |
| 48504 | Massachusetts Peace Action Education Fund Inc. | 1 | $69,992 | 1 |
| 48505 | Massachusetts Port Authority | 1 | $150,000 | 1 |
| 48506 | MASSACHUSETTS SCHOOL BUILDING AUTHORITY | 1 | $81,562 | 1 |
| 48507 | Massachusetts Society of Certified Public Accountants, Inc. | 1 | $83,000 | 1 |
| 48508 | Massa Multimedia Architecture PC | 1 | $67,000 | 1 |
| 48509 | Massar Capital Management, LP | 1 | $200,000 | 1 |
| 48510 | MassChallenge, Inc. | 1 | $178,683 | 1 |
| 48511 | Massena Hospital, Inc. | 1 | $406,593 | 1 |
| 48512 | Mass General Brigham Health Plan | 1 | $156,229 | 1 |
| 48513 | Mass General Brigham Medical Group Northern Massachusetts, Inc. | 1 | $270,000 | 1 |
| 48514 | Massivit 3D Inc. | 1 | $90,000 | 1 |
| 48515 | MassLight, Inc. | 1 | $176,800 | 1 |
| 48516 | Massman Construction Co. | 1 | $73,507 | 1 |
| 48517 | MassPay Holdings LLC | 1 | $180,000 | 1 |
| 48518 | Massumi Consoli LLP | 1 | $390,000 | 1 |
| 48519 | Mast Drug Co., Inc. | 1 | $143,250 | 1 |
| 48520 | MasTec Civil, LLC | 1 | $90,000 | 1 |
| 48521 | Mastech Digital Consulting Inc. | 1 | $100,402 | 6 |
| 48522 | Mastech Digital Systems, Inc. | 1 | $108,826 | 6 |
| 48523 | MasTec Utility Services, LLC | 1 | $91,600 | 1 |
| 48524 | Mas Tek IT, LLC | 1 | $61,173 | 1 |
| 48525 | MASTEK IT, LLC | 1 | $105,227 | 1 |
| 48526 | MasterBrand, Inc. | 1 | $160,000 | 1 |
| 48527 | MASTER BUILDERS SOLUTIONS ADMIXTURES US, LLC | 1 | $161,526 | 1 |
| 48528 | Master Capital Partners LLC | 1 | $175,000 | 1 |
| 48529 | MASTERCARD MOBILE TRANSACTIONS SOLUTIONS INC | 1 | $138,000 | 1 |
| 48530 | Mastercard Transaction Services (US) LLC | 1 | $138,000 | 1 |
| 48531 | Mastercars Auto Group, Inc. | 1 | $100,000 | 1 |
| 48532 | Master Chemical Corporation | 1 | $178,000 | 1 |
| 48533 | Master CVV Technologies LLC | 1 | $118,000 | 1 |
| 48534 | Master Forwarding Network, Inc. | 1 | $75,255 | 1 |
| 48535 | Master Informatix Systems, Inc. | 1 | $118,456 | 1 |
| 48536 | Master International Corporation | 1 | $155,000 | 1 |
| 48537 | Master International Corporation, Inc. | 1 | $75,000 | 1 |
| 48538 | Master Klass Academy LLC | 1 | $48,776 | 1 |
| 48539 | Master Manufacturing Company, Inc. | 1 | $65,000 | 1 |
| 48540 | Masterpiece Auto LLC | 1 | $88,837 | 1 |
| 48541 | MASTER POOL & HOME CLEANING INC | 1 | $80,558 | 1 |
| 48542 | Master Power Transmission Inc. | 1 | $93,500 | 1 |
| 48543 | Masterprep Academy Franching LLC | 1 | $72,800 | 1 |
| 48544 | Masterprep Academy Franchising LLC | 1 | $97,000 | 1 |
| 48545 | Master Prep Academy LLC | 1 | $79,040 | 1 |
| 48546 | Masterprep Academy Seattle LLC | 1 | $86,000 | 1 |
| 48547 | Master RIA LLC | 1 | $175,000 | 1 |
| 48548 | Master Steel, LLC | 1 | $80,000 | 1 |
| 48549 | Master's Transportation, Inc. | 1 | $50,000 | 1 |
| 48550 | MASTERTATSE INC. | 1 | $105,144 | 1 |