| A M P Tree Service INC | Michael Joseph Pacelli | — | (909) 931 0111 | Tree | Upland · San Bernardino County | — | — |
| A N A Building Maintenance | A N A Building Maintenance | — | (840) 216 8519 | Electricians | Fontana · San Bernardino County | — | — |
| A N C Landscaping Services | Navarette Cortez Alejandro | — | (760) 651 9051 | Windows, patio, painters | Victorville · San Bernardino County | — | — |
| A N Palacios Plumbing INC | Jose Vladimir Palacios Morales | — | (562) 641 6307 | Other | Rialto · San Bernardino County | — | — |
| A New Dawn Construction INC | Dawn Marie Vredenburg | — | (909) 224 5073 | GC, remodel, ADU | Pinon Hills · San Bernardino County | — | — |
| A O - Kay Glass And Screen | Christopher Micheal Kay | — | (909) 874 1140 | Windows, patio, painters | Rialto · San Bernardino County | — | — |
| A O Construction & Renovations | Julio Cesar Aguirre Almirez | — | (909) 257 7556 | GC, remodel, ADU | San Bernardino · San Bernardino County | — | — |
| A O Dowd Plumbing INC | Jason Matthew Dowd | — | (909) 684 1915 | Other | Fontana · San Bernardino County | — | — |
| A O Electric | Ochoa Arthur | — | (909) 810 9069 | Electricians | Yucaipa · San Bernardino County | — | — |
| A O Kraft INC | Andrew Nicholas Jr Ornelas | — | (909) 915 4310 | GC, remodel, ADU | San Bernardino · San Bernardino County | — | — |
| A P Cabinets INC | Jose Humberto Aguirre | — | (909) 454 2443 | Other | San Bernardino · San Bernardino County | — | — |
| A P G Builders INC | Pinto Mejia Alejandro | — | (909) 764 9343 | GC, remodel, ADU | Fontana · San Bernardino County | — | — |
| A P L Professional Landscapes | A P L Professional Landscapes | — | (909) 264 5294 | Windows, patio, painters | Yucaipa · San Bernardino County | — | — |
| A Perfect Touch Painting LLC | Matthew Martinez | amy@aperfecttouchpainting.com | (909) 977 2220 | Windows, patio, painters | Chino · San Bernardino County | — | — |
| A Plus Asphalt Paving INC | Adolfo Eduardo Valdez | — | (747) 322 2679 | Other | Upland · San Bernardino County | — | — |
| A Plus Drywall | A Plus Drywall | — | (949) 886 4471 | Other | San Bernardino · San Bernardino County | — | — |
| A Plus Sign Shops INC | Kevin Joseph Payment | — | (909) 434 6975 | Other | Rancho Cucamonga · San Bernardino County | — | — |
| A Plus Sprinkler And Landscape Service | Villaescusa Andrew | — | (909) 553 8407 | Windows, patio, painters | Crestline · San Bernardino County | — | — |
| A Precision Builder | A Precision Builder | aprecisionbuilder@gmail.com | (760) 985 4863 | GC, remodel, ADU | Apple Valley · San Bernardino County | — | — |
| A R Electric | Alex David Ramirez | — | (909) 226 1880 | Electricians | Rancho Cucamonga · San Bernardino County | — | — |
| A R Electrical & Plumbing INC | Antonio Israel Lauro | — | (951) 533 5903 | Electricians | San Bernardino · San Bernardino County | — | — |
| A R Joens Plumbing | A R Joens Plumbing | arjonesplumbing@gmail.com | (909) 496 6324 | Other | Big Bear City · San Bernardino County | — | — |
| A R M Electric | Rodger Lyn Ashby | — | (760) 954 0228 | Electricians | Hesperia · San Bernardino County | — | — |
| A R Refrigeration | A R Refrigeration | — | (909) 510 2146 | HVAC | Rancho Cucamonga · San Bernardino County | — | — |
| A Rack Company | Omar Alejandro Sanchez Perez | — | (818) 858 6379 | Other | Victorville · San Bernardino County | — | — |
| A S A P Glasswerks | A S A P Glasswerks | — | (213) 435 3545 | Windows, patio, painters | Fontana · San Bernardino County | — | — |
| A S C Flooring Incorporated | Alejandro Saldivar | — | (909) 614 9488 | Other | Chino · San Bernardino County | — | — |
| A S T Advanced Service Technology INC | Frank Fay Fahey | — | (909) 966 9080 | Other | Colton · San Bernardino County | — | — |
| A Schuman Electric | Andrew Nathen Schuman | — | (760) 628 5249 | Electricians | Lucerne Valley · San Bernardino County | — | — |
| A Second Opinion Plumbing | A Second Opinion Plumbing | — | (909) 437 7747 | Other | San Bernardino · San Bernardino County | — | — |
| A Sound Vision & Automation | A Sound Vision & Automation | — | (626) 242 6048 | Other | Upland · San Bernardino County | — | — |
| A T J Construction | Tania Erendira Anaya | — | (909) 957 3335 | GC, remodel, ADU | Rancho Cucamonga · San Bernardino County | — | — |
| A T M Custom Wood Floors INC | Tania Zenaida Carmona | — | (818) 625 5361 | Other | San Bernardino · San Bernardino County | — | — |
| A T Pearl Electric | Turner Doyle | info@atpearlelectric.com | (760) 330-5323 | Electricians | Rancho Cucamonga · San Bernardino County | — | — |
| A T S Construction | Edward James Marquez | — | (909) 322 7202 | GC, remodel, ADU | Ontario · San Bernardino County | — | — |
| A T W Construction INC | Michael Aaron Wilhoit | — | (760) 256 6451 | GC, remodel, ADU | Barstow · San Bernardino County | — | — |
| A To Z Construction | Michael William Parker | — | (760) 964 1728 | GC, remodel, ADU | Hesperia · San Bernardino County | — | — |
| A V Excellence | A V Excellence | — | (310) 938 3733 | Other | Hesperia · San Bernardino County | — | — |
| A V Fence | A V Fence | — | (760) 508 1995 | Other | Hesperia · San Bernardino County | — | — |
| A V L Concrete Breaking | Maria Elena Ortega | — | (213) 949 1747 | Other | Fontana · San Bernardino County | — | — |