| A & R Construction | Amir Aatari Sharghi | — | (909) 451 1031 | GC, remodel, ADU | Rialto · San Bernardino County | — | — |
| A & R Plastering | A & R Plastering | — | (760) 947 5443 | Other | Hesperia · San Bernardino County | — | — |
| A & R Tarpaulins INC | Kenneth Glenn Weisbart | — | (909) 829 4444 | Other | Fontana · San Bernardino County | — | — |
| A & R Welding And Repair | Reyes Angel | — | (760) 493 0157 | Other | Hesperia · San Bernardino County | — | — |
| A & Son's Concrete INC | Armando Medina Jr Vargas | — | (909) 282 2164 | Other | Ontario · San Bernardino County | — | — |
| A + Air Corp | Gary David Long | — | (909) 821 6359 | HVAC | Rancho Cucamonga · San Bernardino County | — | — |
| A + Electric | Enrique Jr Lopez | — | (310) 350 8151 | Electricians | Upland · San Bernardino County | — | — |
| A + Millwork Casework Installations | Montoya Ricardo | — | (951) 642 1851 | Other | Fontana · San Bernardino County | — | — |
| A - 1 Door | A - 1 Door | — | (760) 995 6621 | Other | Victorville · San Bernardino County | — | — |
| A - 1 Garage Doors & Repairs | Jeffrey Joseph Mccarthy | — | (909) 355 1376 | Other | Rancho Cucamonga · San Bernardino County | — | — |
| A - 1 Plumber | A - 1 Plumber | — | (760) 242 4737 | Other | Apple Valley · San Bernardino County | — | — |
| A - 1 Pools INC | Nicolas George Terlip | — | (909) 931 9396 | Pool | Upland · San Bernardino County | — | — |
| A - Advantage Plumbing | A - Advantage Plumbing | — | (909) 790 5900 | Other | Yucaipa · San Bernardino County | — | — |
| A - C Reglazing | A - C Reglazing | — | (909) 973 0988 | Other | Ontario · San Bernardino County | — | — |
| A - Cap Cabinetry | A - Cap Cabinetry | — | (626) 422 4824 | Other | Sugarloaf · San Bernardino County | — | — |
| A - Industrial Design / Build | Andrew Jason Hernandez | — | (213) 290 0091 | GC, remodel, ADU | Ontario · San Bernardino County | — | — |
| A - Plus Septic And Drain | Eric James Adams | — | (760) 844 2523 | Other | Yucca Valley · San Bernardino County | — | — |
| A - Plus Tec Construction Co | Joshua Seung Il Lee | — | (626) 833 8873 | GC, remodel, ADU | Chino Hills · San Bernardino County | — | — |
| A 1 Construction Co | Kwang Hyun Paek | — | (714) 797 9000 | GC, remodel, ADU | Phelan · San Bernardino County | — | — |
| A 2 Z Plumbing | A 2 Z Plumbing | — | (909) 758 6237 | Other | Ontario · San Bernardino County | — | — |
| A A A Electric & Elevator INC | Jen Shou Huang | — | (626) 523 7978 | Electricians | Fontana · San Bernardino County | — | — |
| A A B Innovation Construction & Remodel INC | Becerril Rangel Alberto | — | (909) 714 8499 | GC, remodel, ADU | San Bernardino · San Bernardino County | — | — |
| A A Construction | Wayne Arnett | — | (909) 421 7960 | Other | Rialto · San Bernardino County | — | — |
| A A Electric | Oscar Armando Alvarez | — | (714) 492 3761 | Electricians | Hesperia · San Bernardino County | — | — |
| A A Electrical Service | Alan Wayne Addie | — | (310) 714 6915 | Electricians | Fontana · San Bernardino County | — | — |
| A A L S Landscape INC | Anthony Albiero | — | (909) 631 7323 | Windows, patio, painters | Chino · San Bernardino County | — | — |
| A A Martin | A A Martin | — | (909) 291 5554 | Electricians | Rancho Cucamonga · San Bernardino County | — | — |
| A And E Heating And Air Conditioning INC | Adam Michael Sauerbrun | — | (909) 835 0709 | HVAC | Yucaipa · San Bernardino County | — | — |
| A And F Mcguire Electric Co | Adam Christopher Mcguire | — | (909) 252 8644 | Electricians | Chino Hills · San Bernardino County | — | — |
| A Avco Plumbing - Heating - A/c | Frederick Dale Ballard | — | (909) 822 8000 | HVAC | Fontana · San Bernardino County | — | — |
| A B C Glass & Screens INC | Petrovic Vladimir | — | (760) 245 8355 | GC, remodel, ADU | Victorville · San Bernardino County | — | — |
| A B C Heating & Air Conditioning | Thomas Anthony Riordan | — | (909) 730 0753 | HVAC | Chino Hills · San Bernardino County | — | — |
| A B C Seating INC | John Roy Baum | — | (760) 247 7347 | Other | Lucerne Valley · San Bernardino County | — | — |
| A B F Construction INC | Anthony Bruce Forcier | — | (909) 425 4277 | GC, remodel, ADU | Redlands · San Bernardino County | — | — |
| A Barron Painting | A Barron Painting | — | (951) 505 3395 | Windows, patio, painters | Fontana · San Bernardino County | — | — |
| A Better Choice Development INC | Daniel Osvaldo Mangaroni | — | (909) 931 1007 | GC, remodel, ADU | Upland · San Bernardino County | — | — |
| A Better Connection - Plus | A Better Connection - Plus | — | (310) 918 0729 | Other | Rancho Cucamonga · San Bernardino County | — | — |
| A Better Fire Restoration | Daniel Osvaldo Mangaroni | — | (909) 931 1007 | GC, remodel, ADU | Upland · San Bernardino County | — | — |
| A Builders California INC | Craig Michael Larsen | — | (323) 719 0872 | GC, remodel, ADU | Phelan · San Bernardino County | — | — |
| A C A Painting | A C A Painting | — | (909) 829 3541 | Windows, patio, painters | Fontana · San Bernardino County | — | — |