| Lee-way Construction INC | Dennis Keith Lee | — | (209) 736 4192 | GC, remodel, ADU | Altaville · Calaveras County | — | — |
| Lester Construction | John Ray Lester | — | (925) 519 5134 | GC, remodel, ADU | Valley Springs · Calaveras County | — | — |
| Level Up Electrical | James Edward Jr Sacher | — | (209) 743 2918 | Electricians | Mountain Ranch · Calaveras County | — | — |
| Lewis Custom Building | Lewis Custom Building | — | (415) 225 3133 | GC, remodel, ADU | Arnold · Calaveras County | — | — |
| Livanos Landscaping | Livanos Landscaping | — | (209) 743 3770 | Windows, patio, painters | Altaville · Calaveras County | — | — |
| Lone Pine Tree Service | Jillian Ann Job | a_joel92@yahoo.com | (209) 371 7873 | Other | Valley Springs · Calaveras County | — | — |
| Loomis Drywall | Loomis Drywall | — | (209) 736 4740 | Other | Altaville · Calaveras County | — | — |
| Lopes Construction | Rick Anthony Lopes | interested@domainmarket.com | (209) 785 4750 | GC, remodel, ADU | Copperopolis · Calaveras County | — | — |
| Los Angeles Drywall | Los Angeles Drywall | — | (714) 486 6948 | GC, remodel, ADU | San Andreas · Calaveras County | — | — |
| Loving Touch Design & Remodeling | Keith Owen Ancar | — | (209) 872 1084 | GC, remodel, ADU | Mountain Ranch · Calaveras County | — | — |
| Lucido Drilling | Lucido Drilling | — | (925) 584 1141 | Other | Arnold · Calaveras County | — | — |
| Lumin Construction | Austin Lee Fouts | — | (209) 817 4584 | Other | Copperopolis · Calaveras County | — | — |
| Lusk Electric | Lusk Electric | 4luskelectric@gmail.com | (209) 900-7666 | Electricians | Copperopolis · Calaveras County | — | — |
| Luxantixor LuxantixorroofingProtected | Luxantixor Luxantixorroofing | — | (864) 910-0117 | Tile roofers | Carlsbad · Calaveras County | — | — |
| Lynn Kelly Cleaning | Lynn Kelly Cleaning | — | (209) 747 5305 | Other | Burson · Calaveras County | — | — |
| M A D Electric | Michael Bruce Madrid | — | (209) 304 4138 | Electricians | Valley Springs · Calaveras County | — | — |
| M A Leonard Construction INC | Mark Anthony Leonard | — | (209) 763 5531 | GC, remodel, ADU | Wallace · Calaveras County | — | — |
| M K N Enterprises | Mark Elton Nunnelley | — | (209) 728 8815 | Electricians | Murphys · Calaveras County | — | — |
| Mainline Plumbing Enterprises INC | Nicklos Joseph Ciolino | — | (650) 580 2315 | Other | Valley Springs · Calaveras County | — | — |
| Mark Hunter Construction | Mark Leonard Hunter | contact@sansoxygen.com | (650) 465 9157 | GC, remodel, ADU | Arnold · Calaveras County | — | — |
| Mark Miles Well Drilling | Mark Miles Well Drilling | — | (209) 728 8212 | Other | Murphys · Calaveras County | — | — |
| Martin Bf Lynch | Martin Bf Lynch | — | (209) 286 1590 | Other | Mokelumne Hill · Calaveras County | — | — |
| Martin Tubb | Martin Tubb | — | (925) 642 3670 | GC, remodel, ADU | Avery · Calaveras County | — | — |
| Marty's Do-it-for-ya | Marty's Do-it-for-ya | — | (209) 890 0393 | GC, remodel, ADU | Mountain Ranch · Calaveras County | — | — |
| Masonry Unlimited INC | Michael Kenneth Saiers | interested@domainmarket.com | (209) 603 7170 | Other | Valley Springs · Calaveras County | — | — |
| Mast & Sons Plumbing | Ryan Michael Mast | — | (209) 663 5043 | Other | San Andreas · Calaveras County | — | — |
| Matison Roofing Co | Cody John Matison | — | (209) 785 2666 | Other roofers | Angels Camp · Calaveras County | — | — |
| Matt Mcginnis Restoration | Matt Mcginnis Restoration | matt@mattmcginnisrestoration.com | (909) 772 3533 | GC, remodel, ADU | Angels Camp · Calaveras County | — | — |
| Matt Mcintosh Painting | Matt Mcintosh Painting | — | (209) 329 3393 | Windows, patio, painters | Valley Springs · Calaveras County | — | — |
| Matt Miller Construction | Matt Justin Miller | — | (209) 754 0223 | GC, remodel, ADU | San Andreas · Calaveras County | — | — |
| Maul Electric | John Jr Maul | — | (209) 404 0260 | Electricians | Hathaway Pines · Calaveras County | — | — |
| Maximum Power INC | David Edward Steele | — | (209) 824 2741 | Electricians | San Andreas · Calaveras County | — | — |
| Maynard Management INC | Maynard Management INC | — | (209) 293-2225 | Property managers | West Point · Calaveras County | — | — |
| Mc Cain Construction | Gerald William Mc Cain | — | (209) 603 3331 | GC, remodel, ADU | Wallace · Calaveras County | — | — |
| Mc Clain Company | Thomas Lee Mc Clain | — | (209) 763 5274 | Other | Wallace · Calaveras County | — | — |
| Mc Tague Excavating | Mc Tague Excavating | — | (209) 795 7642 | Other | Hathaway Pines · Calaveras County | — | — |
| Medina's Landscaping Maintenance | Medina's Landscaping Maintenance | — | (209) 728 7202 | Windows, patio, painters | Angels Camp · Calaveras County | — | — |
| Metal & More INC | Catherine Ann Uhlinger | — | (209) 772 0301 | GC, remodel, ADU | Valley Springs · Calaveras County | — | — |
| Metal Mike Steel Building Construction INC | Michael Donald Sr Uhlinger | — | (209) 608 5986 | GC, remodel, ADU | Valley Springs · Calaveras County | — | — |
| Metildi Electric INC | Craig Thomas Metildi | — | (916) 337 6744 | Electricians | Murphys · Calaveras County | — | — |