| King Builds Corp | A, B | 2026 | Active |
| Kingdom Builders GC LLC | B | 2026 | Active |
| Kingsmen Construction Inc. | B | 2019 | Active |
| Kitchell / Cem Inc | B + C10, C20, C36 | 2010 | Active |
| Kitchen Art Inc | B | 2025 | Active |
| Kitchen Design Studio | B + C6 | 2024 | Active |
| Kitchen Mart Kitchen & Bath Remodeling | B | 1978 | Active |
| Kline-Youngblood Construction | B + C36 | 1984 | Active |
| Kmax LLC | B | 2024 | Active |
| KMR Custom Builder Inc | B | 2020 | Active |
| Kompan California Inc | A | 2020 | Renew by Dec 31, 2026 |
| Koslin Construction Incorporated | A | 1995 | Active |
| KR Handyman Services Inc | B, B2 | 2025 | Active |
| Krouse Construction Inc | B | 2025 | Active |
| KWK Solutions LLC | B | 2026 | Active |
| L & B Modular Inc | B + C47 | 2004 | Active |
| L G General Contractors Inc | B + C8, C12, C21 +1 | 2002 | Active |
| La Baja Remodeling Services | B2 | 2026 | Active |
| Labor Resource Group Inc | A, B | 2016 | Active |
| Lap Lee | B + C47 | 2018 | Active |
| Larson Industrial Services Inc | A | 2012 | Active |
| Lawson Mechanical Contractors | A, B + ASB, C2, C4 +6 | 1958 | Active |
| Lawson Mechanical Contractors LLC | A, B + ASB, C2, C4 +6 | 2023 | Active |
| Lawson SSP Group LLC | A, B + ASB, C2, C4 +6 | 2023 | Active |
| Lazorko Builders Inc | B | 2007 | Active |
| Lazurka Build | B | 2024 | Active |
| Legacy Windows Incorporated | B + C17 | 2015 | Active |
| Lemida Construction Group | B | 2025 | Active |
| Lemon Tree Construction Inc | B + C10, C36 | 2023 | Active |
| Leo Builder Inc | B | 2025 | Active |
| Lima Design & Remodeling | B2 | 2023 | Active |
| Limitless Construction And Development | B | 2012 | Active |
| Link General Contractors LLC The | B | 2024 | Renew by Dec 31, 2026 |
| Lion Tuff Construction LLC | B | 2025 | Active |
| LMG Builders | B | 2026 | Active |
| Local Community Builders | B | 2022 | Active |
| Logan Proof Builders Inc | B | 2014 | Active |
| Lords Electric Inc | A, B + C10 | 2010 | Active |
| Loya Pena Builders Inc | B + C9 | 2022 | Active |
| Lozano General Contractor Inc | B | 2020 | Active |
| Lund Construction Co | A + HAZ | 1977 | Active |
| Lund Inc | B + C10 | 2025 | Active |
| Lupton Excavation Inc | A | 1992 | Active |
| LV Construction | B | 2026 | Active |
| Lytle Construction Inc | B | 1985 | Active |
| M & M Electric | A + C10 | 1969 | Active |
| M & M General Construction Inc | B | 2021 | Active |
| M & P Elite Construction | B | 2024 | Active |
| M A C Nor Cal Construction Inc | B | 2017 | Active |
| M B M Construction Services Inc | B | 2021 | Active |
| M I B Enterprises Inc | A, B | 1998 | Active |
| M M R Probuilders | B | 2026 | Active |
| M P A Contractors Inc | B | 2008 | Active |
| M S M Construction Inc | B | 2022 | Active |
| M V P Construction Company | B | 2009 | Active |
| M V P Petroleum Engineering Inc | A, B + HAZ | 1999 | Active |
| M3 Mep LLC | A, B + C4, C7, C10 +3 | 2022 | Renew by Nov 30, 2026 |
| M3 Service LLC | A, B + C4, C7, C10 +3 | 2022 | Renew by Dec 31, 2026 |
| Macdougall Builders Inc | B | 2026 | Active |
| Madriago - Lewis Construction Inc | B + C8 | 2002 | Active |
| Main Point Construction Corp | B | 2026 | Active |
| Mano Construction Inc | B | 2018 | Active |
| Manufactured Home Specialists The | B + C47 | 1988 | Active |
| Mark II Builders | B | 2017 | Active |
| Mark III Construction Inc | A, B + C4, C7, C10 +3 | 2010 | Active |
| Marketone Builders Inc | B | 1997 | Active |
| Martin Brothers Construction | A + HAZ | 1996 | Active |
| Martinez Remodeling Contractor Inc | B2 | 2025 | Active |
| Maxlegacy Builders | B2 | 2026 | Active |
| MC Adu Builders, Inc. | B | 2022 | Active |
| MC Clernon General Engineering Inc | A | 1972 | Active |
| MC Clernon Grading And Excavating | A | 2014 | Active |
| McDaid Construction Inc | B | 2025 | Active |
| MD Construction & Restoration | B | 2011 | Active |
| MD Construction Of Sacramento LLC | B | 1992 | Active |
| Meadows Construction Inc | B | 2018 | Active |
| Medical Craftsman Home Services LLC | B | 2025 | Active |
| Melick Art Roofing | B + C39 | 1981 | Active |
| Menderix Building Solutions | B + C10 | 2025 | Active |
| Mendez Saucedo Construction Inc | B | 2019 | Active |
| Meritage Homes Of California Inc | B | 1998 | Active |
| Miguel & Son's Construction Inc | B | 2024 | Active |
| Milestone Plumbing | B | 2025 | Active |
| Millennium Termite & Pest | B | 1999 | Active |
| Miller's General Building Contractor And Associates LLC | B | 2022 | Renew by Nov 30, 2026 |
| Mills Builders Inc | B + C21 | 2000 | Active |
| Mind's Eye Construction | B | 2025 | Active |
| Miranda's Construction And Remodeling LLC | B | 2021 | Active |
| MLR Construction Co LLC | B | 2023 | Active |
| Modern Home Pros Construction | B | 2024 | Active |
| Modero Construction Inc | B + D41 | 2021 | Active |
| Montelongo Ed Construction LLC | B | 2024 | Active |
| Moran's Construction Inc | B | 2017 | Active |
| Morph Builders Inc | B | 2025 | Active |
| Moser Michael Development Inc | B + C13 | 2018 | Active |
| Mosko Home Improvement | B | 2023 | Active |
| Most Built Construction | B | 2020 | Active |
| Mountainpeak Construction Inc | B | 2026 | Active |
| Mrogers Remodeling Inc | B2 | 2024 | Active |
| Mt Higgins Construction | B | 2023 | Active |