| M Bay Area Construction Inc | B | 2010 | Active |
| M C O Engineering | A, B + C31, C51 | 2013 | Active |
| M C S Construction Services | B | 2016 | Active |
| M E C Construction Division | B + C36 | 2006 | Active |
| M F Construction And Renovation Inc | B | 1999 | Active |
| M G Construction | B | 2014 | Renew by Dec 31, 2026 |
| M H Construction Management Co | A, B + ASB, C10, C33 +1 | 1989 | Active |
| M H T Construction Inc | B | 2010 | Active |
| M L General Construction | B | 2004 | Active |
| M Moser Associates LLC | B | 2015 | Active |
| M N Construction Inc | B | 2004 | Renew by Dec 31, 2026 |
| M P H Building Contractor Inc | B | 2016 | Active |
| M Squared Construction Inc | A | 2006 | Active |
| M T Construction Inc | B | 2013 | Active |
| M V Construction | B + C10, C36 | 1990 | Active |
| M Z Development | B | 2020 | Renew by Dec 31, 2026 |
| Ma Kee Painting Inc | B + C33 | 2010 | Active |
| Mac Builders LP | B | 2023 | Active |
| Mac Tec Construction Company Inc | A, B + C10, C16, C20 +2 | 2014 | Renew by Dec 31, 2026 |
| Maca Builders Incorporated | B | 1989 | Active |
| Maclean Donald S Incorporated | A + C8 | 1985 | Active |
| Macro Builder Inc | B | 2001 | Active |
| Macs SF | B | 2022 | Active |
| Macworks Construction | B | 2024 | Active |
| Madrone Construction Resources LLC | B + C21 | 2017 | Active |
| Magnitude Builders Inc | B | 2020 | Active |
| Majestic Construction | B + C9 | 1991 | Active |
| Makita Construction Inc | B | 2009 | Active |
| Malcolm Drilling Company Inc | A + C57, D09 | 1969 | Active |
| Mardah Realty Group LLC | B | 2026 | Active |
| Marina Seismic | A | 2011 | Active |
| Marinship Development Interest LLC | A, B + C31, HAZ | 2016 | Active |
| Marquez Builders | B | 2022 | Active |
| Martin Building Co | B | 1989 | Active |
| Martinez Jose General Construction Inc | B | 2016 | Renew by Dec 31, 2026 |
| Marview Maintenance LLC | B | 2025 | Active |
| Master Builders | A, B | 2004 | Active |
| Master Fixers Construction Inc | B | 2025 | Active |
| Matarozzi / Pelsinger Builders Inc | B | 1998 | Active |
| Matthew Kelly Construction Inc | B | 2021 | Active |
| Mava Studio Inc | B | 2024 | Active |
| Maven Maintenance Inc | B | 2006 | Active |
| Maverick Remodel Builder Inc | B | 2026 | Active |
| Maxg Construction Inc | B | 2021 | Active |
| Maximo Construction LLC | B + C27 | 2000 | Active |
| MC Carthy A Engineering Inc | A + C8 | 1998 | Active |
| MC Construction Services | B + C10, C36 | 2026 | Active |
| MC Elroy Stephen Construction LLC | B | 2021 | Active |
| MC Gee & MC Gee Construction Corp | B | 2000 | Active |
| MC Millan Electric | B + C10 | 1971 | Active |
| McCartney Restoration Painting & Waterproofing Inc | B + C33 | 1990 | Active |
| MCG Engineering Group Inc | A, B | 2025 | Active |
| McGuinness McCann Group | B | 2021 | Active |
| McMahon Construction LLC | B | 2003 | Active |
| McNulty Construction Inc | B + C8 | 1999 | Active |
| MD Buildworks | B | 2023 | Active |
| MDW Group Associates, LLC | B | 2026 | Active |
| Meb Construction Inc | B | 2023 | Active |
| Meca Builders Inc | B + C9 | 2008 | Active |
| Mech 23 Inc | B + C20, C36 | 2019 | Active |
| Mendez-Ortiz Construction Inc | B | 2016 | Renew by Dec 31, 2026 |
| Merlo Lewis M Inc | A, B + C8, C12, D06 | 1959 | Active |
| Mesa Construction Inc | B + C10 | 1993 | Active |
| Mesa Construction LLC | B | 1977 | Active |
| Metasilicon Construction Inc | B + C10 | 2024 | Active |
| Method Design - Build LLC | B + C10, C36 | 2024 | Active |
| Metzler Brothers General Contractors Inc | B | 2014 | Active |
| MG Construction LLC | B | 2025 | Active |
| Mhy Construction Inc | B | 2024 | Active |
| Mi Sharp Corporation | B + D28 | 2019 | Active |
| Michael Carroll Construction Inc | B | 2016 | Active |
| Michael Heavey Construction Inc | A | 2004 | Active |
| Microestimating Inc | A, B | 2005 | Active |
| Millwright Construction Inc | B | 2024 | Active |
| Minerva Engineering | A, B + HAZ | 2012 | Active |
| Minihane Construction | A | 2024 | Active |
| Mint Construction Inc | B | 2025 | Active |
| Mission Constructors Inc | A, B + C31 | 2012 | Active |
| Mission Home Remodeling Inc | B | 2021 | Active |
| Mitchell Engineering | A, B + C10, C31, C36 +1 | 1998 | Active |
| Mizen Construction Inc | B | 2012 | Active |
| Modern Builder Construction Inc | B | 2022 | Active |
| Modern Construction Inc | B | 2004 | Active |
| Modern Craft Construction Inc | B | 2013 | Active |
| Modern Inspiration Construction | B | 2025 | Active |
| Modern Technology Resources Inc | A, B + C27, C36, C57 +1 | 2011 | Active |
| Modern Vision Construction Inc | B + C16, C36 | 2025 | Active |
| Molloy Concrete | A + C8 | 2007 | Active |
| Momentum Construction & Development LLC | B | 2024 | Active |
| Monblue Construction Inc | B + C17 | 2018 | Renew by Nov 30, 2026 |
| Mone Construction Co Inc | B | 2020 | Active |
| Monolith Construction Inc | B | 2004 | Active |
| Mora Custom Builder Construction | B | 2018 | Active |
| Moroso Construction Inc | B | 2000 | Active |
| Motif Makers And Builders | B | 2020 | Active |
| Mount Street Construction | B | 2021 | Active |
| Mountain Top Construction LLC | B | 2019 | Active |
| MRCC | B | 2003 | Active |
| MRR Ca CM LLC | B | 2022 | Active |
| Mta Construction Inc | B | 2024 | Active |