| Artesan Construction | Michel Blane Stevens | — | (650) 400 7160 | GC, remodel, ADU | Redwood City · San Mateo County | — | — |
| Arthulia INC | Arthur Gordon Wong | — | (650) 302 8625 | Electricians | Millbrae · San Mateo County | — | — |
| Arthur Mosqueda Construction | Mosqueda Arthur | — | (650) 888 5792 | GC, remodel, ADU | San Bruno · San Mateo County | — | — |
| Arthur Ng Construction | Arthur Chi Ping Ng | — | (415) 806 8833 | GC, remodel, ADU | Millbrae · San Mateo County | — | — |
| Arthur R Rapues Painting | Arthur R Rapues Painting | — | (415) 378 8461 | Windows, patio, painters | So San Francisco · San Mateo County | — | — |
| Artisan Builders | Artisan Builders | — | (650) 455 7747 | GC, remodel, ADU | Millbrae · San Mateo County | — | — |
| Artisan Plumbing | Artisan Plumbing | — | (650) 608 1045 | Other | Montara · San Mateo County | — | — |
| Artisan Woodworking | Artisan Woodworking | — | (650) 589 2903 | Other | South San Francisco · San Mateo County | — | — |
| Artist Construction | Wingo Y C Siu | — | (415) 760 8296 | GC, remodel, ADU | San Mateo · San Mateo County | — | — |
| Artistic Garage Doors INC | Oliverio Paredes | — | (650) 594 1183 | GC, remodel, ADU | San Carlos · San Mateo County | — | — |
| Arts Finishing | Arts Finishing | — | (650) 802 1189 | Windows, patio, painters | San Carlos · San Mateo County | — | — |
| Artush Floor Covering LLC | Muradyan Artak | — | (408) 892 4640 | Other | Atherton · San Mateo County | — | — |
| Asap Plumbing Pro | Asap Plumbing Pro | service@asapplumbingpro.com | (415) 728 6391 | Other | South San Francisco · San Mateo County | — | — |
| Asap Plumbing Pros LLC | Donald St Cheng | — | (415) 728 6391 | Other | South San Francisco · San Mateo County | — | — |
| Asborno Construction | Dean George Asborno | — | (650) 255 2147 | GC, remodel, ADU | Portola Valley · San Mateo County | — | — |
| Asc Construction Services INC | Scott Fernando Mencaccy | dmencaccy@ascconstructionservices.com | (650) 321 2894 | GC, remodel, ADU | Menlo Park · San Mateo County | — | — |
| Asf Electric INC | Cathleen Marie Lagomarsino | — | (650) 755 9032 | Electricians | Daly City · San Mateo County | — | — |
| Ash Brothers Construction INC | Allen David Ash | — | (415) 971 0679 | GC, remodel, ADU | Redwood City · San Mateo County | — | — |
| Ash Mountain Gc INC | Ramon Yusu Qiu | ramon@ashmountaingc.com | (925) 386 4274 | GC, remodel, ADU | Daly City · San Mateo County | — | — |
| Asia K Kan DBA A K A Construction Co | Asia Kwok Hung Kan | — | (415) 850 8488 | GC, remodel, ADU | Hillsborough · San Mateo County | — | — |
| Assisi Demolition INC | Michael Anthony Perez | — | (650) 278 6337 | Other | Burlingame · San Mateo County | — | — |
| Associated Electric & Security INC | William Hayden Koester | — | (650) 347 5551 | Electricians | South San Francisco · San Mateo County | — | — |
| Associated Security Alarm Co | William Hayden Koester | — | (650) 347 5551 | Electricians | Burlingame · San Mateo County | — | — |
| Associated Trucking INC | Tracy James Fitzgerald | — | (650) 652 3960 | GC, remodel, ADU | Brisbane · San Mateo County | — | — |
| Assure Msp Low Voltage | Scott Nelson Snyder | — | (888) 410 4888 | Other | San Mateo · San Mateo County | — | — |
| Atherton Builders INC | Caesar Young | — | (650) 575 6076 | GC, remodel, ADU | Atherton · San Mateo County | — | — |
| Atherton Electric INC | David Michael Aknin | — | (650) 670 0784 | Electricians | San Carlos · San Mateo County | — | — |
| Atlantis Remodeling | Atlantis Remodeling | contact@atlantis-remodeling.com | (650) 598 0345 | GC, remodel, ADU | Belmont · San Mateo County | — | — |
| Atlas Heating & Ventilating Co | Geoffrey Sutton Tuck | — | (650) 873 7000 | HVAC | South San Francisco · San Mateo County | — | — |
| Atlas/pellizzari Electric INC | Jeffery James Gormley | — | (650) 364 1204 | Electricians | Redwood City · San Mateo County | — | — |
| Atodor LLC | Vilius Baksevicius | atodorllc@gmail.com | (650) 307 7538 | Other | Millbrae · San Mateo County | — | — |
| Atpoint INC | Masaya Kanno | info@atpoint.com | (650) 338 1230 | Other | San Mateo · San Mateo County | — | — |
| Atrium Handyman & Construction | Hani Nakleh Aho | — | (650) 222 5040 | GC, remodel, ADU | Redwood City · San Mateo County | — | — |
| Audio Production Group INC | Andrew Craig Heller | — | (650) 207 2162 | Other | Redwood City · San Mateo County | — | — |
| Augustino Electric | Carson Heller Augustino | — | (415) 640 6598 | Electricians | Daly City · San Mateo County | — | — |
| Aurora's Construction INC | Morales Rios Andres | — | (650) 346 2423 | GC, remodel, ADU | Redwood City · San Mateo County | — | — |
| Automated Shading & Blinds | Automated Shading & Blinds | — | (650) 235-1871 | Windows, patio, painters | San Mateo · San Mateo County | — | — |
| Automatic Door Systems INC | Stephanie Roehm Gotelli | — | (650) 592 8282 | Other | San Carlos · San Mateo County | — | — |
| Avedas Build INC | Angel Rogelio Whaley Aguilar | — | (650) 771 4599 | GC, remodel, ADU | Redwood City · San Mateo County | — | — |
| Avelar Corp | Aaron Ross Avelar | — | (650) 750 7338 | GC, remodel, ADU | Burlingame · San Mateo County | — | — |