| Madsen Homes INC | Christen Nathan Madsen | team@madsen.homes | (435) 523-1010 | GC, remodel, ADU | Corona · Riverside County | — | — |
| Madz Co | Marco Antonio Diaz | — | (858) 449 2982 | GC, remodel, ADU | Winchester · Riverside County | — | — |
| Madz Construction INC | Marco Antonio Diaz | — | (858) 449 2982 | GC, remodel, ADU | Winchester · Riverside County | — | — |
| Maec Construction LLC | Mario Alberto Escobedo Canovas | — | (951) 772 3802 | GC, remodel, ADU | San Jacinto · Riverside County | — | — |
| Maestro Builders & Contractors | Raul Lanuza | — | (616) 558 9722 | GC, remodel, ADU | Corona · Riverside County | — | — |
| Maestro Carpintero | Maestro Carpintero | — | (760) 485 8097 | GC, remodel, ADU | Palm Desert · Riverside County | — | — |
| Maestro Contractor Services | Lanuza Raul | — | (616) 558 9722 | GC, remodel, ADU | Corona · Riverside County | — | — |
| Mag Wire Electric | Connor Robert Maguire | — | (951) 837 1925 | Electricians | Murrieta · Riverside County | — | — |
| Magana Construction Group | Magana Benitez Alan | — | (310) 878 7890 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| Magic Mechanical Plumbing INC | Jason Allen Shier | — | (714) 307 5900 | Other | Temecula · Riverside County | — | — |
| Magic Snake Pro INC | J Jesus Moreno Carreon | — | (951) 545 8466 | Other | Corona · Riverside County | — | — |
| Magic Snake Pro INC | Jason Max Kay | — | (888) 538 4238 | Other | Corona · Riverside County | — | — |
| Magic Touch | Magic Touch | — | (951) 549 8708 | Other | Corona · Riverside County | — | — |
| Magic Touch Tree Care | Jaime Mota | — | (951) 737 1203 | Tree | Norco · Riverside County | — | — |
| Magic Turf | Magic Turf | — | (951) 490 9410 | Other | Temecula · Riverside County | — | — |
| Magics Heating And Air LLC | Francisco De Jesus Anaya | — | (951) 225 5705 | HVAC | Lake Elsinore · Riverside County | — | — |
| Magik Glass And Door | Timothy James Hicks | — | (760) 325 1876 | Windows, patio, painters | Palm Springs · Riverside County | — | — |
| Magnesite & Diato Service | Vladimirov Vanjuan | — | (818) 917 8832 | Windows, patio, painters | Mecca · Riverside County | — | — |
| Magnolia Heating & Cooling INC | Eric Daniel Smith | — | (951) 688 3524 | HVAC | Riverside · Riverside County | — | — |
| Magnolia Landscape | Magnolia Landscape | — | (951) 323 3965 | Windows, patio, painters | Moreno Valley · Riverside County | — | — |
| Magnum HVAC | Magnum HVAC | — | (714) 329 2340 | HVAC | Riverside · Riverside County | — | — |
| Magnus Pools And Spas Enterprise | Magnus Pools And Spas Enterprise | — | (951) 318 3387 | Pool | Moreno Valley · Riverside County | — | — |
| Maher Communications | Juan Maldonado | — | (951) 343 1347 | Electricians | Riverside · Riverside County | — | — |
| Maier Construction INC | Oliver Marius Maier | — | (714) 402 9833 | GC, remodel, ADU | Norco · Riverside County | — | — |
| Main Line Roofing INC | Sanchez Bernardo Guereca | — | (951) 421 6735 | Other roofers | Moreno Valley · Riverside County | — | — |
| Mainline Engineering Services INC | Nicholas Andrew Marshall | — | (714) 331 1510 | Other | Norco · Riverside County | — | — |
| Mainline Irrigation | Mainline Irrigation | — | (626) 331 3168 | Windows, patio, painters | Lake Elsinore · Riverside County | — | — |
| Majestic Construction | Justin Anthony Bodor | — | (909) 838 4101 | GC, remodel, ADU | Norco · Riverside County | — | — |
| Majestic Electrical Services | Janette Melendez | — | (626) 264 7663 | Electricians | San Jacinto · Riverside County | — | — |
| Majestic Plumbing INC | Ivan Scott Bodor | — | (951) 750 0654 | Other | Riverside · Riverside County | — | — |
| Majestic Pool Construction | Orbelio Caridad Rodriguez | — | (951) 458 2128 | Pool | Canyon Lake · Riverside County | — | — |
| Majestic Process Technology INC DBA Jp Machinery And Pumps | Jose Padilla | — | (619) 212 9371 | Other | Murrieta · Riverside County | — | — |
| Majestic Shutters INC | Todd Russell Kinder | — | (760) 346 1957 | Other | Indio · Riverside County | — | — |
| Majestic Sign Studio | Gordon Manuel Jr Wolfe | — | (951) 735 5001 | Other | Corona · Riverside County | — | — |
| Major Air Solutions | Major Air Solutions | — | (951) 476 5282 | HVAC | San Jacinto · Riverside County | — | — |
| Major Leak Plumbing INC | Larry Frank Desaulniers | — | (951) 696 9993 | Other | Lake Elsinore · Riverside County | — | — |
| Mak Construction INC | Fernando Mazkiaran Martinez | — | (424) 462 8007 | GC, remodel, ADU | Corona · Riverside County | — | — |
| Make A Friend Construction | Peng He | — | (626) 413 7780 | GC, remodel, ADU | Eastvale · Riverside County | — | — |
| Makeover Landscape LLC | Yalina Rivera | — | (951) 623 3685 | Windows, patio, painters | Perris · Riverside County | — | — |
| Makeover Landscape LP | Yalina Rivera | — | (951) 623 3685 | Windows, patio, painters | Perris · Riverside County | — | — |