| Pedersen Patrick Inc | B | 2013 | Active |
| Penn Construction Inc | B | 2019 | Active |
| Perrilliat Enterprises Inc | A, B | 2021 | Active |
| Petersen Les Drilling & Pump Inc | A + C55, C57, D21 | 1970 | Renew by Dec 31, 2026 |
| Pimentel Paving Inc | A + C12 | 1990 | Active |
| Pine Creek Development Corporation | B | 1981 | Active |
| PK Max Inc | B + D63 | 2019 | Active |
| Platinum Construction & Millwork Inc | B + C6 | 2004 | Active |
| Polley George Construction LLC | B | 1992 | Active |
| Poppy Design Build Inc | B | 2023 | Active |
| Power Pole Service Inc | B + C10, D31 | 2017 | Active |
| Precise Framing | B | 2009 | Active |
| Precision Build Corporation | B + C17 | 1990 | Active |
| Prestige Homes & Remodel Inc | B | 2000 | Active |
| Prexa Electrical Contractor | B + C10 | 2012 | Active |
| Promise Energy Inc | B | 2012 | Active |
| Promise Energy Inc/Eagle Environmental Construction & Development | A, B + HAZ | 2025 | Active |
| Provision Enterprise Inc | B | 2026 | Active |
| Pumpman Norcal | A + C10, C16, C55 +2 | 2017 | Active |
| Purofirst Of Sonoma County | B | 2006 | Renew by Dec 31, 2026 |
| Qualified Builders Construction | B | 2022 | Renew by Dec 31, 2026 |
| Quality & Precision Construction Inc | B | 2025 | Active |
| Quality Builders And Renovation Inc | B | 2025 | Active |
| Quantum Mechanical Of Sonoma County Inc | B + C16, C36 | 1997 | Active |
| R E R Construction Inc | B + C54 | 2007 | Active |
| R H B Builders LLC | B | 2015 | Active |
| R J Wade Construction Inc | B | 2002 | Active |
| R N Construction | B | 2016 | Active |
| R R Builder Inc | B | 2022 | Active |
| Ramirez Builders Inc | B | 1998 | Renew by Dec 31, 2026 |
| Ramm General Construction | B | 2025 | Active |
| Ramos Property Services LLC | B | 2026 | Active |
| Ray & Associates | B | 2022 | Active |
| Raztec Inc | B | 2024 | Active |
| RB Contracting LLC | A + C10 | 2026 | Active |
| Red Oak Contracting LLC | B | 2025 | Active |
| Redi | B + C15, C47, D64 | 2018 | Active |
| Reliable Crane & Rigging Inc | A + D21, D36 | 2013 | Active |
| Remodel Restoration Remediation | B2 | 2026 | Active |
| Renew By Redwood LLC | B2 | 2026 | Active |
| Rental Rehab Inc | B + C8 | 2004 | Active |
| Resendiz Construction Inc | B | 2021 | Active |
| Restoration Construction | B | 2021 | Active |
| RH Land Solutions LLC | A | 2021 | Active |
| Ridgeview Builders Inc | B | 1999 | Active |
| Riva And Cal Construction Inc | A, B | 2021 | Active |
| RK West | B | 2025 | Active |
| RL Builders Inc | A, B | 2006 | Active |
| Roberts Service & Construction | A + C4, C10, C20 +1 | 1989 | Active |
| Romo's Construccion Inc | B | 2021 | Active |
| Ross Recreation Equipment Company Inc | A + D34 | 1987 | Active |
| Ruiz Construction & Management Inc | B | 2020 | Renew by Dec 31, 2026 |
| Rydr Construction LLC | B | 2026 | Active |
| S B G C Inc | B | 2012 | Active |
| Saint Joseph Construction | B | 2024 | Renew by Dec 31, 2026 |
| Sal Gen Con Inc | B | 2000 | Active |
| Sanctuary North Inc | B | 2022 | Active |
| SC Barns Buildings And Fence | B + C13 | 2020 | Renew by Dec 31, 2026 |
| Sccmd LLC | B | 2026 | Active |
| Schaefer Engineering Inc | A | 2012 | Active |
| Schellinger Construction Co | B | 1977 | Active |
| Scuderi Builders Inc | B | 2003 | Active |
| SH Siteworks | A | 2024 | Active |
| Shannon Masonry Construction Inc | B + C29 | 1988 | Active |
| Shri Hari Development Inc | B | 2021 | Active |
| Sierra Pipeline Inc | A | 2002 | Active |
| Signature Builders Inc | B | 2025 | Active |
| Sikes Asphalt Group Inc | A + C32 | 2003 | Active |
| Silver Lining Construction Inc | B | 1998 | Active |
| SK Unlimited Construction Inc | B + C21 | 2022 | Active |
| Sky Builders Inc | B + C10 | 2005 | Active |
| Skyview Tree Experts Inc | A + C27, C31, C49 +1 | 2022 | Active |
| Smeltz George Construction Inc | B | 2010 | Active |
| Soco General Construction | B | 2025 | Active |
| Solano Construction Inc | B | 2026 | Active |
| Solid Point Construction & Consulting Inc | B | 2021 | Active |
| Sonoma County General Construction | B | 2023 | Active |
| Sonoma County Sunrooms | B | 2001 | Active |
| Sonoma Residential Services LLC | B | 2021 | Active |
| Sonoma Siteworks & Engineering Inc | A | 2023 | Active |
| Soriano's Custom Builder Inc | B | 2023 | Active |
| Stagecoach Development Co Inc | B | 1979 | Active |
| Stillpoint Inc | A, B | 1992 | Active |
| Sundriver Construction LLC | B | 2021 | Active |
| Suntegrity Solar | B + C10, C46 | 1977 | Active |
| Synergy Construction LLC | A, B | 2015 | Active |
| T C Castle Construction Inc | B | 2008 | Active |
| T R L Builders Inc | B | 2021 | Active |
| Taf Building & Design Inc | B + C33, D42 | 2012 | Renew by Dec 31, 2026 |
| Tee Vax | B | 2003 | Active |
| The Brothers That Just Do Gutters Coastal North Ca | B + C43 | 2023 | Active |
| The Cabinet Outlet | B | 2018 | Active |
| The Crawl Space Guys | B | 2005 | Active |
| The Rock Construction Inc | B + C8 | 2020 | Renew by Dec 31, 2026 |
| Third Pig Builder Inc | B | 1983 | Active |
| Tibbens Frank H Construction Inc | B | 1992 | Active |
| Tillman Construction Inc | A | 1984 | Active |
| TM Construction Inc | B | 2020 | Active |
| TML Electric LLC | B + C10 | 2025 | Active |
| Top Shelf Builders | B | 2025 | Active |