| Mazon Electric | Mazon Salinas Ricardo | — | (415) 828 6576 | Electricians | Richmond · Contra Costa County | — | — |
| Mazotti Construction | Christopher Joseph Mazotti | — | (925) 726 1605 | GC, remodel, ADU | Oakley · Contra Costa County | — | — |
| Mazzamuto Construction | James Salvatore Mazzamuto | — | (925) 766 9917 | GC, remodel, ADU | Martinez · Contra Costa County | — | — |
| Mazzamuto Construction INC | James Salvatore Mazzamuto | — | (925) 228 7376 | GC, remodel, ADU | Martinez · Contra Costa County | — | — |
| Mbm Renovations | Villalobos Brayn Celis | — | (415) 595 2705 | GC, remodel, ADU | Richmond · Contra Costa County | — | — |
| Mc Allister Construction | Preston Lee Mc Allister | — | (925) 864 7013 | GC, remodel, ADU | Discovery Bay · Contra Costa County | — | — |
| Mc Carthy Construction | Jeffrey Frank Mc Carthy | doug@mccarthyconstruction.com | (515) 240-4884 | GC, remodel, ADU | Clayton · Contra Costa County | — | — |
| Mc Carthy Construction | Anthony Charles Mc Carthy | doug@mccarthyconstruction.com | (515) 240-4884 | GC, remodel, ADU | San Pablo · Contra Costa County | — | — |
| Mc Carty Landscape & Gardening | Mc Carty Landscape & Gardening | — | (925) 825 8686 | Windows, patio, painters | Concord · Contra Costa County | — | — |
| Mc Cauley Construction | Gary David Mc Cauley | — | (925) 381 2605 | GC, remodel, ADU | Martinez · Contra Costa County | — | — |
| Mc Cauley's Electrical Services | Glen Roy Mc Cauley | — | (925) 383 2597 | Electricians | Pittsburg · Contra Costa County | — | — |
| Mc Coy & Sons Const | Mc Coy & Sons Const | — | (925) 200 2487 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Mc Curley's Floor Center INC | Mohamad Kazem| Etemadi Casey Etemadi | — | (925) 680 7538 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Mc Dermott Construction | Anthony Joseph Mc Dermott | — | (415) 205 3651 | GC, remodel, ADU | Brentwood · Contra Costa County | — | — |
| Mc Donald Professional | Mc Donald Professional | — | (510) 332 3888 | GC, remodel, ADU | Alamo · Contra Costa County | — | — |
| Mc Guire Electric | Michael David Mc Guire | — | (925) 980 3413 | Electricians | San Ramon · Contra Costa County | — | — |
| Mc Ilroy Construction | David Alan Mc Ilroy | — | (925) 818 7345 | GC, remodel, ADU | Pleasant Hill · Contra Costa County | — | — |
| Mc Laughlin Construction | Edward Francis Iii Mc Laughlin | — | (925) 348 2661 | GC, remodel, ADU | Martinez · Contra Costa County | — | — |
| Mc Lean Construction | Jack Lyn Mc Lean | — | (510) 804 9221 | GC, remodel, ADU | El Sobrante · Contra Costa County | — | — |
| Mc Peak Electric INC | Sean Matthew Mc Peak | — | (925) 229 3473 | Electricians | Martinez · Contra Costa County | — | — |
| Mca Flow Plumbing | Mca Flow Plumbing | — | (415) 571 3606 | Other | Richmond · Contra Costa County | — | — |
| Mcbride's Building And Restoration | Mcbride's Building And Restoration | — | (209) 814 0708 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Mcc Drywall | Mcc Drywall | — | (925) 755 6725 | Other | Oakley · Contra Costa County | — | — |
| Mccarthy Sheetmetal | Mccarthy Sheetmetal | — | (925) 676 6312 | Other | Concord · Contra Costa County | — | — |
| Mccartt Construction INC | Ian Grant Mc Cartt | — | (925) 858 4469 | GC, remodel, ADU | Clayton · Contra Costa County | — | — |
| Mcconnell Construction | Sean Brian Mcconnell | — | (925) 250 2898 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Mccullough Construction | David Robert Mccullough | — | (925) 325 6781 | GC, remodel, ADU | Brentwood · Contra Costa County | — | — |
| Mcdonough Construction | Carl Patrick Mc Donough | — | (925) 584 1932 | GC, remodel, ADU | Discovery Bay · Contra Costa County | — | — |
| Mce Corporation | Steven Gregory Loweree | — | (925) 803 4111 | GC, remodel, ADU | Concord · Contra Costa County | — | — |
| Mcgeehan Portable Welding And Fabrication | Mcgeehan Portable Welding And Fabrication | — | (650) 222 5640 | Other | Antioch · Contra Costa County | — | — |
| Mch Construction INC | Mauro Alberto Chavez Hernandez | — | (415) 529 8003 | GC, remodel, ADU | Walnut Creek · Contra Costa County | — | — |
| Mchale's Environmental Insulation INC | Daniel Victor Hair | — | (925) 825 9780 | Other | Concord · Contra Costa County | — | — |
| Mckay & Co Construction | Kent Harrison Mc Kay | — | (925) 229 8900 | GC, remodel, ADU | Martinez · Contra Costa County | — | — |
| Mckenzie Finishes INC | Howard Frank Mc Kenzie | — | (510) 204 9116 | GC, remodel, ADU | Richmond · Contra Costa County | — | — |
| Mckenzie Gray INC | James L Gray | jim@mckenziegray.com | (925) 284 2100 | GC, remodel, ADU | Lafayette · Contra Costa County | — | — |
| Mclear Builders INC | Marcelino Gonzalez | — | (925) 852 9300 | GC, remodel, ADU | Antioch · Contra Costa County | — | — |
| Mcm Plumbing INC | Quintero Carlos Hernandez | — | (415) 797 8096 | Other | Antioch · Contra Costa County | — | — |
| Mcmahon Construction Services INC | Daniel Shannon Mc Mahon | — | (925) 855 1185 | GC, remodel, ADU | Danville · Contra Costa County | — | — |
| Mcnamara Development And Construction INC | Timothy Michael Mcnamara | — | (925) 285 1944 | GC, remodel, ADU | Lafayette · Contra Costa County | — | — |
| Mcneil & Sons Fire Safety | Harry Walter Kern | — | (925) 464 8102 | Other | Walnut Creek · Contra Costa County | — | — |