| M C Construction | Jose Luis Avelar | — | (951) 703 5097 | Pool | Mira Loma · Riverside County | — | — |
| M C Electric | Chirita Mihai | — | (714) 396 4240 | Electricians | Corona · Riverside County | — | — |
| M C I D Concrete INC | Diego Alejandro De La Torre | — | (619) 882 8566 | Other | Perris · Riverside County | — | — |
| M C I General Building DBA Morales Contracting | Morales Marcial Ysidro | — | (951) 966 0555 | GC, remodel, ADU | Nuevo · Riverside County | — | — |
| M C I Plumbing Corp | Juan Manuel Cabral | — | (951) 453 1999 | Other | Riverside · Riverside County | — | — |
| M C L Tile Marble & Granite | Mario A Aguilar | — | (760) 288 5066 | Other | Desert Hot Springs · Riverside County | — | — |
| M C S Modern Combined Services | Miller Duane | — | (951) 656 3939 | Other | Moreno Valley · Riverside County | — | — |
| M C Tile & Stone INC | Martin Noel Carbajal | — | (760) 404 0344 | Other | Palm Desert · Riverside County | — | — |
| M D C Electric | Michael David Cooper | — | (760) 774 3364 | Electricians | Bermuda Dunes · Riverside County | — | — |
| M D Electric | Douglas Albert Knight | — | (760) 327 5024 | Electricians | Cathedral City · Riverside County | — | — |
| M D Fixall | M D Fixall | — | (760) 613 4231 | GC, remodel, ADU | La Quinta · Riverside County | — | — |
| M D Installations International INC | Melissa Arlene Mejia | — | (951) 737 5019 | Other | Corona · Riverside County | — | — |
| M D T INC | Ashlee Olivia Mejia | — | (951) 232 0904 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| M E A Construction INC | Annalocia C Elkhoury | — | (951) 830 6386 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| M E R Construction | Michael Eugene Regus | — | (714) 334 1641 | GC, remodel, ADU | Temecula · Riverside County | — | — |
| M Fitts Construction Co | Gary Lee Schwarzenbach | info@mfittsconstruction.com | (951) 534 5051 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| M Foremost Roofing | Geraldit Jeaneth Hernandez | — | (951) 348 2150 | Other roofers | Hemet · Riverside County | — | — |
| M G A Tile & Stone | Garcia Moises | — | (909) 963 2011 | Other | Mira Loma · Riverside County | — | — |
| M G B Construction INC | Jon Alan Beach | — | (951) 342 0303 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| M G Landscape A Partnership | Jose Nicolas Avitia | — | (760) 636 2725 | Windows, patio, painters | Palm Desert · Riverside County | — | — |
| M G R Concrete INC | Jesus Manuel Garcia Romero | — | (760) 578 9506 | Other | Desert Hot Springs · Riverside County | — | — |
| M G Roofing | Soriano Guzman Manuel | — | (951) 662 3473 | Other roofers | Moreno Valley · Riverside County | — | — |
| M Galvan Plumbing INC | Manuel Puga Galvan | — | (760) 578 8087 | Other | Indio · Riverside County | — | — |
| M Goldman General Maintenance | Jesse David Jon Macias | — | (760) 880 7162 | GC, remodel, ADU | Cathedral City · Riverside County | — | — |
| M H Construction | Hagedorn Michael | — | (760) 464 7008 | GC, remodel, ADU | Cathedral City · Riverside County | — | — |
| M H I Pros | David Blake Smith | — | (951) 588 8979 | Other | Riverside · Riverside County | — | — |
| M H R Plumbing | M H R Plumbing | — | (760) 660 1257 | Other | Desert Hot Springs · Riverside County | — | — |
| M Hearn Electric LLC | Michael Robert Hearn | — | (951) 385 5046 | Electricians | Moreno Valley · Riverside County | — | — |
| M J Lath And Plastering | M J Lath And Plastering | — | (951) 313 0199 | Other | Riverside · Riverside County | — | — |
| M J Paving | M J Paving | — | (800) 932 6200 | Other | Perris · Riverside County | — | — |
| M J Pipeline Construction | Jose Ascencion Lucero | — | (951) 934 3180 | Other | Jurupa Valley · Riverside County | — | — |
| M J Pittman Construction | Michael John Pittman | — | (951) 500 2855 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| M J Plastering INC | Miguel Perez Jacobo | — | (714) 834 1600 | Other | Riverside · Riverside County | — | — |
| M J R Tile | M J R Tile | — | (951) 488 2758 | Other | Canyon Lake · Riverside County | — | — |
| M J S Plumbing | M J S Plumbing | — | (951) 760 6200 | Other | Murrieta · Riverside County | — | — |
| M J W Framing INC | Joshua Allen Wills | — | (909) 353 8010 | GC, remodel, ADU | Calimesa · Riverside County | — | — |
| M J Welding & Fabrication | M J Welding & Fabrication | — | (909) 262 2892 | Other | Temecula · Riverside County | — | — |
| M K Drywall | M K Drywall | — | (951) 252 7539 | Other | Wildomar · Riverside County | — | — |
| M K Installations General Contractors | Michael Craig Kuri | — | (949) 378 4670 | GC, remodel, ADU | Lake Elsinore · Riverside County | — | — |
| M K Kennard Electric | Michael Kevin Kennard | — | (951) 236 8054 | Electricians | Riverside · Riverside County | — | — |