| American Telesource INC | Michael John Peterson | — | (510) 428 1111 | Other | Oakland · Alameda County | — | — |
| American Trash Management INC | Steven Allen Seltzer | — | (415) 292 5400 | GC, remodel, ADU | Emeryville · Alameda County | — | — |
| American Universal Construction | Phat Hong Tran | — | (510) 306 8401 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| American Water Heater Service INC | Steven Michael Mills | sarah@americanwaterheaterservice.com | (510) 490 4411 | HVAC | Newark · Alameda County | — | — |
| American West Pavers | American West Pavers | — | (510) 314 5942 | Other | Hayward · Alameda County | — | — |
| American Wholesale Lighting INC | Etten Benjamin Van | — | (510) 252 1088 | Electricians | Livermore · Alameda County | — | — |
| Ameritex Elevator West LLC | Jerry Alfred Matheny | — | (844) 646 9660 | Other | Hayward · Alameda County | — | — |
| Amermex Construction INC | Luis Manuel Anaya | — | (510) 209 6441 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Amethyst Lathing & Plastering INC | Salvador Robert Perez | — | (510) 314 6478 | Other | Hayward · Alameda County | — | — |
| Amex Sheet Metal INC | Steven Glen Ragsdale | — | (408) 941 3405 | Other | Hayward · Alameda County | — | — |
| Amg | Brent Allen Bates | — | (510) 654 8441 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Ami Contracting | Angel Manuel Irizarry | — | (925) 580 0727 | GC, remodel, ADU | Pleasanton · Alameda County | — | — |
| Amigo Garage Doors INC | Ruelas Rodriguez Ramiro | — | (925) 784 5104 | Other | Livermore · Alameda County | — | — |
| Amigo Landscaping Tree Service | Palomarez Alejandro | — | (510) 552 4110 | Windows, patio, painters | Fremont · Alameda County | — | — |
| Amigo Rooter & Plumbing | Amigo Rooter & Plumbing | — | (925) 640 2071 | Other | Livermore · Alameda County | — | — |
| Amir Amiri Construction | Amiri Amir | — | (408) 694 3472 | Electricians | Hayward · Alameda County | — | — |
| Amir Construction | Kidron Yochai | — | (510) 928 5148 | GC, remodel, ADU | Berkeley · Alameda County | — | — |
| Amj Quality Construction INC | Zhao Cong | — | (510) 417 6339 | GC, remodel, ADU | Newark · Alameda County | — | — |
| Amor Plumbing | Amor Plumbing | — | (408) 649 3129 | HVAC | Fremont · Alameda County | — | — |
| Amped Electrical Systems | Carlos Alfonso Guzman | — | (510) 935 4699 | Electricians | Hayward · Alameda County | — | — |
| Amplified Lifestyles LLC | Casey Robert Webster | info@amplifiedlifestyles.com | (650) 569 1267 | Other | Hayward · Alameda County | — | — |
| Amrom Building | Amrom Building | — | (406) 260 6105 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| Amrut Construction LLC | Pramod Jagubhai Patel | — | (559) 360 3679 | GC, remodel, ADU | Pleasanton · Alameda County | — | — |
| Ams Construction Services | Brian Joseph Dutra | impallari@gmail.com | (925) 399 6867 | GC, remodel, ADU | Pleasanton · Alameda County | — | — |
| Ams.net LLC | Robert Michael Tocci | — | (925) 518 1104 | Electricians | Livermore · Alameda County | — | — |
| Amsterdam Painting & Decorating | Amsterdam Painting & Decorating | — | (510) 490 7999 | Windows, patio, painters | Fremont · Alameda County | — | — |
| Amv General Contractor INC | Morales Villa Armando | — | (510) 213 2493 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| An Construction INC | Michael Steven Phillips | — | (925) 998 8670 | GC, remodel, ADU | Pleasanton · Alameda County | — | — |
| An Thuc Ha | An Thuc Ha | — | (510) 228 2204 | Electricians | San Leandro · Alameda County | — | — |
| Anand Home Improvement | Anand Home Improvement | — | (510) 561 6402 | Windows, patio, painters | Alameda · Alameda County | — | — |
| Anchor Electric INC | Jesse Sloane Rosales | — | (510) 227 5217 | Electricians | Alameda · Alameda County | — | — |
| Anchorpoint Builders | Lemus Cesar Flores | — | (925) 297 9497 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Anderberg Construction Consulting INC | Thomas Arthur Anderberg | — | (510) 482 2779 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Anderson Arbors Corp | Tyler Joseph Anderson | andersonarbors@gmail.com | (925) 525 1110 | GC, remodel, ADU | Livermore · Alameda County | — | — |
| Anderson Commercial Flooring | Joseph Christophe | — | (510) 652 1032 | Other | Oakland · Alameda County | — | — |
| Anderson Construction Group INC | Robert Brooke Anderson | — | (510) 384 7417 | GC, remodel, ADU | Piedmont · Alameda County | — | — |
| Anderson Electric | David Paul Anderson | — | (510) 566 8241 | Electricians | Livermore · Alameda County | — | — |
| Anderson Pro Electric | Andrew Wesley Anderson | — | (925) 800 7800 | Electricians | Livermore · Alameda County | — | — |
| Anderson Restoration INC | Garrett Martorello | — | (408) 748 6005 | GC, remodel, ADU | Newark · Alameda County | — | — |
| Anderson Sewer And Rooter | Anderson Sewer And Rooter | — | (925) 961 2700 | Other | Fremont · Alameda County | — | — |