| Materialink | South Carolina |
| Materialize | New York |
| Materialize Labs | |
| Materials Design | California |
| Materials Research Science and Engineering Center | |
| Materiel Design | |
| Materion Corporation | Ohio |
| Materna Medical | California |
| Maternova, Inc. | Rhode Island |
| Math and Programming | Illinois |
| Math Corporation | Wisconsin |
| Math is Fun | Arizona |
| MATH Venture Partners Management, LLC | Illinois |
| Math-Kal | Minnesota |
| MathCo | |
| Mathematica | |
| Mathematical Association of America | |
| Mathematical Sciences Publishers | California |
| Matheson Education and Training Solutions, LLC | New Hampshire |
| Mathis Electronics, Inc. | North Carolina |
| MathMedia Educational Software, Inc. | Illinois |
| Mathscribe | California |
| MathStories.com | California |
| MathTutor Educational Software, Inc. | Indiana |
| MathWorks | Massachusetts |
| Mati Therapeutics, Inc. | |
| Matia | |
| Matic | |
| Matic Digital | |
| Matica Biotechnology, Inc. | Texas |
| Matik, Inc. | California |
| Matinas Biopharma Holdings, Inc. | |
| Matlen Silver | New Jersey |
| Matmon Internet, Inc. | Arkansas |
| Matr Creative, Inc. | |
| Matric Group | Pennsylvania |
| Matricom | Nevada |
| Matrigen Life Technologies | California |
| Matrisome Bio | |
| MatriSys Bioscience | California |
| Matrivax Research and Development | Massachusetts |
| Matrix Agency, LLC | |
| Matrix Analysis and Applied Linear Algebra | North Carolina |
| Matrix Applications, LLC | |
| Matrix Automation | Ohio |
| Matrix Biomed | California |
| Matrix Executions | |
| Matrix Information Systems, Inc. | Florida |
| Matrix Innovative Systems, Inc. | |
| Matrix Integration | Indiana |