| Luzvin O De Leon Construction Inc | B | 2026 | Active |
| M D B Interiors Inc | B | 2003 | Active |
| Machado Bros Inc | A, B + ASB, C21, HAZ | 1992 | Active |
| Marin McI Remodeling Inc | B2 | 2024 | Active |
| Masterson Bryan Enterprises | A, B + C4, C16, C20 +3 | 1971 | Active |
| MC Devitt Construction | B | 2012 | Active |
| MC Lellan W K Co | A + C21 | 1966 | Active |
| McCready Construction Inc | B | 2005 | Active |
| McGee Brian Construction Inc | B | 2015 | Active |
| McGovern Inc | B | 1996 | Active |
| Midstate Construction Corporation | B | 1946 | Active |
| Midstate Residential Construction Inc | B | 2006 | Active |
| Monks Construction | B | 2026 | Active |
| Moorekraft Builders Inc | B | 2009 | Active |
| Morris Construction | B | 1995 | Active |
| Mountain General Engineering LLC | A | 2021 | Active |
| Natal Modica Construction Inc | B | 2004 | Active |
| Natalini Industries LLC | B + C54 | 2022 | Renew by Dec 31, 2026 |
| Nation Construction And Management Inc | B | 2005 | Active |
| Nelson Construction | A | 1990 | Active |
| Nelson Greg Construction Inc | A | 2021 | Active |
| Nor Cal Solar Construction | B + D34 | 1996 | Active |
| North Bay Grading And Paving | A | 2012 | Active |
| North Bay Landscape Management Inc | B + C27 | 1996 | Active |
| Northbay Craftsmen Inc | B | 2021 | Active |
| Northern Pacific Roofing Inc | B + C39 | 2002 | Active |
| Ohana Construction Inc | B | 2006 | Active |
| Olsen Marr B Inc | B + C8 | 1986 | Active |
| Orion Homes Incorporated | B | 1976 | Active |
| Owens John Services Inc | B + C4, C10, C20 +1 | 1986 | Active |
| Pacific Coast Dredging LLC | A | 2026 | Active |
| Pacific Dirtworx | A | 2016 | Active |
| Park Place Constructors Inc | B + C10 | 1987 | Active |
| Parks Home Improvement LLC | B2 | 2025 | Active |
| Parnow Bros | B | 1991 | Active |
| Paul Michael Company Inc | A + C12, C34, C42 | 1979 | Active |
| Precision Concrete Construction LLC | A, B + C8 | 2017 | Active |
| Precision Line Construction Inc | B | 2026 | Active |
| Pruett Fence Company Inc | B + C13 | 1999 | Active |
| Pryor Contractors | B | 2022 | Active |
| R & J Bros Construction | B | 2025 | Active |
| Rafael And Sons Construction Inc | A | 2026 | Active |
| Range Builders | B | 2015 | Active |
| Rebel Pipelines General Engineering Inc | A | 2026 | Active |
| Rebuilding Together Petaluma Inc | B | 2024 | Active |
| Redbridge Electric Inc | B + C10 | 2021 | Active |
| Redwood Builders | B | 2016 | Active |
| Rise Rigging LLC | A | 2019 | Active |
| Roberts Ken & Son General Contractor Inc | B | 1988 | Active |
| Roca Construction Inc | B | 1999 | Active |
| Rockin Roofers | B + C10, C39, C46 | 2014 | Active |
| Rodas Brothers Construction Incorporated | B | 2022 | Active |
| S L M Builders | B | 1996 | Renew by Dec 31, 2026 |
| S W Quality Builders A Partnership | B | 2023 | Active |
| Same Day Plumbing And Water Cleanup | B + C36 | 2026 | Active |
| Satori Construction | B | 2024 | Active |
| Save Energy Co | B + C2, C17 | 1983 | Active |
| Schilly Construction Inc | B | 2004 | Active |
| Schmidt R Construction Inc | B | 2011 | Active |
| Setting The Standard Construction Inc | A | 2024 | Active |
| Sheeran Builders Inc | B | 2023 | Active |
| Sierra Coast Builders Inc | B | 2016 | Active |
| Signor Construction | B | 2024 | Renew by Nov 30, 2026 |
| Sonoma Demolition LLC | B + C21 | 2022 | Active |
| Sonoma-Marin Construction | A, B + C8 | 1994 | Active |
| Spye Conservation Incorporated | A + C27 | 2025 | Active |
| Stephens Properties Inc | B + C9, C35 | 1993 | Active |
| Steven Allen Construction & Developing Inc | B | 2020 | Active |
| Sticks & Stones Construction Inc | B | 2023 | Active |
| Studio 101 General Building Contractors | B | 2017 | Active |
| Sullivan Professional Construction Inc | B | 2018 | Active |
| Superior Building | B + C10, HAZ | 2008 | Active |
| Tap Construction | A, B + C12 | 2019 | Active |
| Team Ghilotti Inc | A + HAZ | 2007 | Active |
| Thomson Contracting Inc | B + C9 | 2019 | Active |
| TLC Custom Home Builders LLC | B | 2026 | Active |
| Tomrose Construction Inc | B | 1990 | Active |
| Trainor Commercial Construction Inc | B + C9 | 1984 | Active |
| Tri County Design Center | B + C15, C54 | 2014 | Active |
| Underscore Design And Build | B | 2024 | Active |
| Union Pacific Construction Inc | B | 1994 | Active |
| Unity Building & Electric Co | B + C10 | 2012 | Renew by Dec 31, 2026 |
| Valencia Kristine Guillermo J Valencia | B | 2007 | Active |
| Wedge Roofing Inc | B + C2, C39, C43 +1 | 1982 | Active |
| West Biofuels LLC | A | 2020 | Active |
| Wildcat Engineering | A | 2010 | Active |
| Will Will Construction Corp | B | 2025 | Active |
| Wilo Construction Co | B | 2025 | Active |
| Zarco's Electrical Inc | B + C10 | 2017 | Active |