| M B S General Construction | B | 2019 | Renew by Dec 31, 2026 |
| M V L Construction Inc | B | 2004 | Active |
| Macro-Z-Technology Company | A, B + HAZ | 1989 | Active |
| Main Street Construction | B | 2021 | Active |
| Maintenance Inc | B | 2010 | Active |
| Marcelo Construction Inc | B | 2023 | Active |
| Marconi Construction Corp | B | 2026 | Active |
| Marne Construction Inc | B + C8 | 1994 | Active |
| Marrokings Brothers LLC | B | 2025 | Active |
| Marsh M J Construction Inc | B + C17 | 1982 | Active |
| Martin Stairways Inc | B + C6 | 2008 | Active |
| Marvista Construction | B + C39 | 1999 | Active |
| Mas - I Construction & Builder | B | 2017 | Active |
| Mason General Builders Inc | B | 2025 | Active |
| MC Duff/Daniels Inc | B + C17 | 1990 | Active |
| McDonald Construction Inc | B | 2017 | Active |
| MD Constructor Inc | B | 2022 | Renew by Dec 31, 2026 |
| Me Premier Painting Inc | B + C33 | 2010 | Active |
| MFK Construction And Maintenance Inc | B | 2019 | Active |
| MKC Construction Inc | B | 2021 | Active |
| MM Construction & Property Services LLC | B | 2026 | Active |
| Monbri Construction Services Inc | B | 2020 | Active |
| Moorefield Construction Inc | B | 1980 | Active |
| Mora Construction Group Inc | B | 2025 | Active |
| Moreno Construction Services Inc | B + C27, C33, D12 | 2009 | Active |
| Murray's Ace Hardware Inc | B + D08, D52 | 2000 | Active |
| Neek LLC | A, B | 2012 | Active |
| New Star Construction Services Inc | B + C6 | 2018 | Active |
| New West Remodelers Builders Designers Inc | B | 1985 | Active |
| Nexus Construction Services Inc | B | 1999 | Active |
| NF Custom Builders Inc | B | 2024 | Active |
| Nieves General Engineering Inc | A, B | 2024 | Active |
| Nipa Inc | A, B + C10 | 1989 | Active |
| Nohan Construction LLC | A + C32 | 2024 | Active |
| Nova Homes Inc | B | 2003 | Active |
| Nova's Construction And Renovation Inc | B | 2014 | Active |
| Nu - Shine Construction Services Inc | B + D12 | 2007 | Active |
| O C Ramps Inc | A, B + C5 | 2014 | Active |
| Oc Finishwood Construction | B | 2026 | Active |
| Ocwest Construction Inc | B | 2025 | Active |
| Odyssey Energy Systems | B + C10 | 2022 | Active |
| Olivaz Construction | A, B | 2026 | Active |
| Omnix Construction LLC | B | 2026 | Active |
| On Point Construction & Renovation Inc | B | 2024 | Active |
| Optimum Remodeling Inc | B | 2022 | Active |
| Optimus Construction LLC | B | 2026 | Active |
| Orange Coast Plumbing | B + C20, C36 | 1990 | Active |
| Orange County General Construction Inc | B | 2025 | Active |
| Orange County Pumping Inc | A, B + C36, C42 | 1993 | Active |
| Original Crank Brothers | B | 2019 | Active |
| Ortega Family Builders Inc | B | 2024 | Active |
| Oso's Construction Corp | B | 2025 | Active |
| P G Pro Construction | B | 2020 | Active |
| Pacific Coast Builders Inc | B | 1993 | Active |
| Pacific Coast Kitchen & Design Inc | B | 1999 | Active |
| Pacific Custom Construction LLC | B | 2022 | Active |
| Pacific General Construction Inc | B | 2022 | Active |
| Pacific Gridline General Engineering | A | 2025 | Active |
| Pacific Landmark Int. | B + C6, C15, C36 +2 | 1992 | Active |
| Pacific Plumbing Company Of Santa Ana | A, B + C4, C16, C20 +3 | 1971 | Active |
| Pacific Sound Control | B + C2, D28, D34 | 1992 | Active |
| Palomar J C Construction Inc | A + C10, HAZ | 2000 | Active |
| Pars Construction And Remodeling Inc | B | 2020 | Renew by Dec 31, 2026 |
| Patriot Heritage Builders LLC | B | 2026 | Active |
| PDC Inc | B | 2013 | Active |
| Pingo Construction Inc | B | 2018 | Active |
| Play Safe Construction Inc | B | 2016 | Active |
| Premier Development Group Inc | B | 2026 | Active |
| Premier Welding And Remodeling Inc | B + C23, C60 | 2025 | Active |
| Prestige Contractors Inc | B | 2023 | Active |
| Prestige Home Design | B | 2026 | Active |
| Q3 Construction Inc | B | 2023 | Active |
| QR Construction LLC | B | 2024 | Active |
| Quail Construction Inc | B | 2007 | Active |
| R & G General Contractor's | B | 1995 | Active |
| Rados Steve P Inc | A, B | 1985 | Active |
| Ramos Construction Group | B | 2025 | Active |
| RB 360 Remodeling Inc | B2 | 2023 | Active |
| RCS Builders | B | 2017 | Active |
| Ready Homes Construction LLC | B | 2020 | Active |
| Reed Thomas Associates LLC | A | 2024 | Active |
| Reed Thomas Company Inc | A + HAZ | 1985 | Active |
| Renova Construction | B + C2 | 2022 | Active |
| RH Renovation's | B2 | 2023 | Active |
| Rice Drywall Inc | B + C9, C21 | 1973 | Active |
| Richards Custom Landscape | B + C27 | 1999 | Active |
| RMS Construction And Remodeling | B | 2025 | Active |
| RMZ Contractor Inc | B | 2025 | Active |
| Roadrunner Exterminating Inc | B | 2008 | Active |
| Roche Excavating Inc | A | 1998 | Active |
| Romans Construction & Restoration Inc | B + C36 | 2022 | Active |
| RT Finish Grading LLC | A | 2023 | Active |
| RVC Pressure Washing | B + D38 | 2026 | Active |
| S A S Constructions | A, B + C10, C31 | 2024 | Active |
| Salgado Remodeling Service And Repair | B | 2025 | Active |
| Salinas Inc | B + C36 | 2007 | Active |
| San Andres Construction Inc | B + C8, C27 | 2024 | Active |
| Sanie Manufacturing Company | B + C51 | 1985 | Active |
| Santa Ana Builders Inc | B | 2024 | Active |
| Santana Family Construction Inc | B + C33 | 2022 | Active |