| LMLuz M. Ortiz | Anasco | PR | Food Manufacturing311999 | — | ◇ UNVERIFIED |
| MFMachucas Family Bakery , Inc. | Cidra | PR | Food Manufacturing311812 | — | ◇ UNVERIFIED |
| MMMacro Mix INC. | Hormigueros | PR | Nonmetallic Mineral Product Manufacturing327320 | — | ◇ UNVERIFIED |
| MAMaga Agricultural LLC | Camuy | PR | Chemical Manufacturing325314 | — | ◇ UNVERIFIED |
| MBMaginas Bakery | Sabana Grande | PR | Food Manufacturing311812 | — | ◇ UNVERIFIED |
| MIMake it Sweet by Anthonella | Toa Alta | PR | Food Manufacturing311811 | — | ◇ UNVERIFIED |
| MDManantial De Amor Bakery LLC | Guayanilla | PR | Food Manufacturing311811 | — | ◇ UNVERIFIED |
| MPMandorle Pasticceria & Panificio LLC | Caguas | PR | Food Manufacturing311811 | — | ◇ UNVERIFIED |
| MDMaria De L Vegatoledo Dba El Artesano Del Pan | Toa Baja | PR | Food Manufacturing311340 | — | ◇ UNVERIFIED |
| MAMario Acevedo Luciano | Isabela | PR | Food Manufacturing311513 | — | ◇ UNVERIFIED |
| MIMaristella INC | Cidra | PR | Apparel Manufacturing315224 | — | ◇ UNVERIFIED |
| MKMarquez Kitchen & More LLC | Cidra | PR | Furniture and Related Product Manufacturing337110 | — | ◇ UNVERIFIED |
| MIMarvel International INC | Guaynabo | PR | Food Manufacturing311611 | — | ◇ UNVERIFIED |
| MMMasa Madre LLC | San Juan | PR | Food Manufacturing311811 | — | ◇ UNVERIFIED |
| MCMassa Corporation | San Juan | PR | Food Manufacturing311824 | — | ◇ UNVERIFIED |
| MPMaster Paint & Chemical INC | Guayanilla | PR | Chemical Manufacturing325510 | — | ◇ UNVERIFIED |
| MRMateo Rivera Jimenez Dba Certenejas Bakery | Cidra | PR | Food Manufacturing311812 | — | ◇ UNVERIFIED |
| MAMayaguez Auto Part | Mayaguez | PR | Fabricated Metal Product Manufacturing332710 | — | ◇ UNVERIFIED |
| MOMayra Ortiz Cruz Dba Lajas Tire & Quick Lube | Lajas | PR | Plastics and Rubber Products Manufacturing326212 | — | ◇ UNVERIFIED |
| MLMc Labs LLC | San Juan | PR | Chemical Manufacturing325411 | — | ◇ UNVERIFIED |
| MHMcneil Health Care LLC | Las Piedras | PR | Chemical Manufacturing325412 | — | ◇ UNVERIFIED |
| MPMedisearchs Pr INC | Guayama | PR | Miscellaneous Manufacturing339113 | — | ◇ UNVERIFIED |
| MPMedtronic Pr Operation CO. | Villalba | PR | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| MPMedtronic Pr Operation Company | Villalba | PR | Computer and Electronic Product Manufacturing334510 | — | ◇ UNVERIFIED |
| MPMedtronic Puerto Rico Operations CO | Humacao | PR | Miscellaneous Manufacturing339113 | — | ◇ UNVERIFIED |
| MPMedtronic Puerto Rico Operations CO | Humacao | PR | Computer and Electronic Product Manufacturing334510 | — | ◇ UNVERIFIED |
| MPMeraki Paper & Plastic Manufacturing LLC | Carolina | PR | Paper Manufacturing322299 | — | ◇ UNVERIFIED |
| MBMercado Bakery INC. | Sabana Grande | PR | Food Manufacturing311812 | — | ◇ UNVERIFIED |
| MSMerck Sharp and Dohme | Arecibo | PR | Chemical Manufacturing325412 | — | ◇ UNVERIFIED |
| MDMerck-sharp Dohme | Barceloneta | PR | Chemical Manufacturing325411 | — | ◇ UNVERIFIED |
| MDMerck-sharp Dohme Arecibo | Arecibo | PR | Chemical Manufacturing325412 | — | ◇ UNVERIFIED |
| MEMetal Equipment of Pr CORP | Catano | PR | Fabricated Metal Product Manufacturing332999 | — | ◇ UNVERIFIED |
 Metal Machining Co., INC | Dorado | PR | Fabricated Metal Product Manufacturing332323 | — | ◇ UNVERIFIED |
| MPMet Pro INC. | Mayaguez | PR | Electrical Equipment, Appliance & Component Manufacturing335313 | — | ◇ UNVERIFIED |
| MRMetzgermeister & Reseach | Ciales | PR | Food Manufacturing311611 | — | ◇ UNVERIFIED |
| MRMetzgermeister & Research CORP | Ciales | PR | Food Manufacturing311612 | — | ◇ UNVERIFIED |
| MCMHL Custom, Inc. | Aguadilla | PR | Miscellaneous Manufacturing339920 | — | ◇ UNVERIFIED |
| MCMi Cocina Gabinetes LLC | Coamo | PR | Furniture and Related Product Manufacturing337110 | — | ◇ UNVERIFIED |
| MOMicrosoft Operations Puerto Rico LLC | Humacao | PR | Computer and Electronic Product Manufacturing334611 | — | ◇ UNVERIFIED |
| MAMiguel A De Jesus Rivera dba MIA UNIFORMS | Caguas | PR | Textile Product Mills314999 | — | ◇ UNVERIFIED |
| MDMillennium Doors and Windows Inc | Isabela | PR | Fabricated Metal Product Manufacturing332321 | — | ◇ UNVERIFIED |
| MDMillennium Doors and Windows Inc. | Isabela | PR | Fabricated Metal Product Manufacturing332321 | — | ◇ UNVERIFIED |
| MJM & J INC | Toa Baja | PR | Chemical Manufacturing325612 | — | ◇ UNVERIFIED |
| MMMlm Macelo La Muda | Guaynabo | PR | Machinery Manufacturing333312 | — | ◇ UNVERIFIED |
| MEMmg Ebenezer INC | Camuy | PR | Food Manufacturing311811 | — | ◇ UNVERIFIED |
| MMM & M Tooling Inc | Patillas | PR | Fabricated Metal Product Manufacturing332710 | — | ◇ UNVERIFIED |
| MCMoca Concrete Poles INC. | Moca | PR | Nonmetallic Mineral Product Manufacturing327390 | — | ◇ UNVERIFIED |
| MIMode Internationale, LLC | San Juan | PR | Apparel Manufacturing315233 | — | ◇ UNVERIFIED |
| MBMontellano's Bakery & Deli Inc. | Cayey | PR | Food Manufacturing311812 | — | ◇ UNVERIFIED |
| MCMoonlight Cookies LLC | Aguadilla | PR | Food Manufacturing311811 | — | ◇ UNVERIFIED |
