| MBM Plumbing Inc | C36 | 2024 | Active |
| MC Dermott Mike Plumbing Inc | C36 | 1995 | Active |
| McDermott Plumbing Inc | C36 | 2025 | Active |
| Meadow Ridge Construction | C36 + B, C10 | 2020 | Active |
| Mectec Inc | C36 + A, B, C10 +1 | 2004 | Active |
| Mega Plumbing Solutions Inc | C36 | 2023 | Active |
| Mejia Royal Plumbing Inc | C36 | 2021 | Active |
| Meoli Rocco Plumbing Contractor Inc | C36 | 1992 | Active |
| Merco Plumbing Co Inc | C36 | 2002 | Active |
| Mergen Construction Inc | C36 + B, C7, C10 +1 | 2006 | Active |
| Mike The Plumber Inc | C36 | 1999 | Active |
| Monroy's Plumbing Inc | C36 | 2023 | Active |
| Morales Rooter & Plumbing Inc | C36 | 2026 | Active |
| Moti Build Inc | C36 + B | 2016 | Active |
| Mr Speedy Plumbing & Rooter Inc | C36 | 2008 | Active |
| Mr Waterworks Inc | C36 + A, B | 2026 | Active |
| Mr. Pipe Works Plumbing Co | C36 | 2018 | Active |
| Mt Plumbing Inc | C36 | 2024 | Active |
| Muir-Chase Plumbing Co Inc | C36 + A, B, C20 | 1988 | Active |
| Namu Group Construction Inc | C36 + B, C10, C20 | 2018 | Active |
| Nautilus Plumbing Inc | C36 | 2011 | Active |
| Neftaly Plumbing Inc | C36 | 2016 | Active |
| New Century Builders And Developers Inc | C36 + B, C10 | 2014 | Active |
| New Era Solutions Plumbing | C36 | 2026 | Active |
| New Pro Plumbing | C36 | 2026 | Active |
| Newland Builders LLC | C36 + B | 2024 | Active |
| Newton Plumbing | C36 | 1998 | Active |
| Nexus Construction & Design Inc | C36 + B, C10, C20 +1 | 2024 | Active |
| Norstar Plumbing & Rooter Inc | C36 | 2006 | Active |
| Novo Maintenance LLC | C36 | 2025 | Active |
| NXT Level Plumbing Inc | C36 | 2025 | Active |
| O K Plumbing Inc | C36 | 1997 | Active |
| O S Plumbing Inc | C36 | 2011 | Active |
| Odell Plumbing Services | C36 + B | 2026 | Active |
| On-Time Royal Plumbing | C36 | 2023 | Active |
| One Way Rooter Services Inc | C36 | 2023 | Active |
| Optimo Plumbing And Backflow Inc | C36 | 2015 | Active |
| Ortega Plumbing Services Inc | C36 | 2023 | Active |
| P And A Electrical Contractors | C36 + C10 | 2011 | Active |
| P D Plumbing Construction Inc | C36 | 2018 | Active |
| Pablo's Plumbing Inc | C36 | 2023 | Active |
| Pacific Plumbing Team Inc | C36 | 2021 | Active |
| Padilla Plumbing Inc | C36 | 1985 | Active |
| Paredes Plumbing Inc | C36 | 2018 | Active |
| Paul Plumbing | C36 | 2000 | Active |
| Perez Construction & Pipelines Inc | C36 + A, B, C10 +1 | 2019 | Active |
| Philmont Management Inc | C36 + A, B, C10 +2 | 2002 | Active |
| Picasso Plumbing | C36 | 1993 | Active |
| Pitman W S & Son Inc | C36 | 1962 | Active |
| Pivotal Plumbing Inc | C36 | 2024 | Renew by Dec 31, 2026 |
| Plan A Plumbing Inc | C36 | 2022 | Active |
| Plumbing & Drain Worx Inc | C36 | 2007 | Active |
| Plumbing Line Inc The | C36 | 2024 | Active |
| Plumbing Rooter For You Inc | C36 | 2024 | Active |
| Precise Plumbing Services | C36 | 1996 | Active |
| Primestone Construction Inc | C36 + B, C10 | 2026 | Active |
| Progreso Plumbing Inc | C36 | 2025 | Active |
| Properly Done Rooter & Plumbing Services Inc | C36 | 2026 | Active |
| Prosperity Development Inc | C36 + B | 2018 | Active |
| Pure-Plumb Plumbing Inc | C36 | 2022 | Active |
| R & D Plumbing & Rooter Inc | C36 | 1999 | Active |
| R A C Construction Inc | C36 + B | 2007 | Active |
| R H Plumbing Inc | C36 | 1993 | Active |
| R M C Construction Electric Inc | C36 + B, C10 | 2011 | Active |
| R P Service Inc | C36 | 2001 | Active |
| R S G Plumbing & Heating Inc | C36 | 2011 | Active |
| Rangel Plumbing | C36 | 2026 | Active |
| Ravello Construction | C36 + B | 2020 | Active |
| Real Choice Management Inc | C36 + B | 2021 | Active |
| Red Lilly Plumbing Inc | C36 + A, C20 | 1963 | Active |
| Rexford Management Group | C36 + B | 2020 | Active |
| Robby's Rooter Inc | C36 | 2000 | Active |
| Robert Ford Plumbing And Heating Inc | C36 | 2016 | Active |
| Rok Plumbing | C36 + B | 2018 | Active |
| Roof Repair & Construction Inc | C36 + B, C39 | 2025 | Active |
| Rooter Ex Inc | C36 | 2017 | Active |
| Rossi Plumbing | C36 + B | 2020 | Active |
| Roth E Z Plumbing Inc | C36 + C16, C42 | 1997 | Active |
| S K Cooling Inc | C36 + B, C10, C20 | 2016 | Renew by Nov 30, 2026 |
| Samwon Construction | C36 + A, B, C10 +4 | 2005 | Active |
| Sea Pac Engineering Inc | C36 + A, B, C10 +2 | 1993 | Active |
| Sergio Plumbing Corp | C36 | 2024 | Active |
| Service Masters | C36 + C20 | 2015 | Active |
| Service Pro Restoration Inc | C36 + B, C10 | 2016 | Active |
| Sewer And Pipeline Contractor Inc | C36 + A, C42 | 2007 | Active |
| Sewer Technicians Of America LLC | C36 | 2025 | Active |
| Shulton City Plumbing Inc | C36 | 2024 | Active |
| Simon Yee Construction Inc | C36 + B | 2009 | Active |
| Smith Mark Construction Inc | C36 + B | 2007 | Active |
| Smith Roy E Plumbing Co Inc | C36 + C16, C20, C42 | 1958 | Active |
| Socal Build And Repair | C36 + B | 2022 | Active |
| Sol Air Conditioning & Heating Inc | C36 + B, C20 | 2006 | Renew by Dec 31, 2026 |
| Steam Equipment Co | C36 + C4, C10 | 1995 | Active |
| Stewart R O Plumbing & Heating Co | C36 + C20 | 1959 | Active |
| Suite Dreams Properties Inc | C36 + B | 2019 | Active |
| Sun West Plumbing Inc | C36 | 2009 | Active |
| Superior Plumbing System & Rooter Inc | C36 | 2013 | Active |
| T S I Plumbing Inc | C36 | 2014 | Active |
| Teague Plumbing | C36 | 2026 | Active |
| Tee's Plumbing Inc | C36 | 2024 | Active |