| A1 Volt INC | Larry Thomas Jr Stinson | — | (760) 475 4014 | Electricians | Oak Hills · San Bernardino County | — | — |
| A2z Builders Group INC | Riaz Ahmad | — | (909) 212 2375 | GC, remodel, ADU | Ontario · San Bernardino County | — | — |
| A4 Painting | A4 Painting | a4paintingcompany@gmail.com | (760) 240 7442 | Windows, patio, painters | Apple Valley · San Bernardino County | — | — |
| Aa HVAC INC | Jinhan Liu | — | (909) 969 0044 | HVAC | Ontario · San Bernardino County | — | — |
| Aa Interlocking Pavers & Concrete Restoration | Christian Andrew Lopez | — | (909) 485 3340 | Restoration | Rancho Cucamonga · San Bernardino County | — | — |
| Aaa Arroyo Air Comfort | Trinidad Jr Velasquez | — | (909) 697 5169 | HVAC | Fontana · San Bernardino County | — | — |
| Aaa Bear Valley Builders INC | Mark Edward Harris | — | (909) 520 8982 | Electricians | Big Bear City · San Bernardino County | — | — |
| Aaa Chengxiang Construction INC | Chong Liu | — | (929) 426 4140 | GC, remodel, ADU | Montclair · San Bernardino County | — | — |
| Aaa Network Solutions INC | Cary Charles Staeden | — | (651) 994 6800 | Electricians | Rancho Cucamonga · San Bernardino County | — | — |
| Aaa Paving Co | Michael Anthony Finazzo | marvin@aaa-paving.com | (405) 714-3564 | Other | Rialto · San Bernardino County | — | — |
| Aaa Plus Construction & Remodeling | Jingsen Huang | — | (951) 903 3598 | GC, remodel, ADU | Chino Hills · San Bernardino County | — | — |
| Aaa Superior Sliding Door Repair | Aaa Superior Sliding Door Repair | — | (951) 288 6378 | Other | San Bernardino · San Bernardino County | — | — |
| Aace's Heating Air Conditioning & Swamp Coolers | Alfred Dale Jr Glover | — | (800) 535 8071 | HVAC | Oak Hills · San Bernardino County | — | — |
| Aaces Heating Air Conditioning And Swamp Coolers | Frank Pulido | — | (800) 535 8071 | HVAC | Oak Hills · San Bernardino County | — | — |
| Aaction Pools | Aaction Pools | — | (909) 486 6102 | Pool | Fontana · San Bernardino County | — | — |
| Aaction Re - Bar Co | Todd Christopher Starkey | — | (909) 815 4491 | Other | Bloomington · San Bernardino County | — | — |
| Aag Pump Services | Armando Arevalo Gonzalez | — | (909) 938 0689 | Other | Ontario · San Bernardino County | — | — |
| Aak Painting Services | Villegas Jonatan Alfonso | — | (909) 961 9055 | Windows, patio, painters | Hesperia · San Bernardino County | — | — |
| Aamir Raza | Aamir Raza | — | (909) 591 7441 | GC, remodel, ADU | Chino · San Bernardino County | — | — |
| Aaron K Anderson | Aaron K Anderson | — | (909) 957 3872 | GC, remodel, ADU | Cedar Glen · San Bernardino County | — | — |
| Aaron Ruston | Aaron Ruston | — | (909) 534 6301 | Electricians | Lake Arrowhead · San Bernardino County | — | — |
| Aaron Velasquez Electric | Aaron Roman Viveros | — | (909) 331 1548 | Electricians | Upland · San Bernardino County | — | — |
| Aaron W Smith Jr | Aaron W Smith Jr | — | (760) 793 5276 | GC, remodel, ADU | Redlands · San Bernardino County | — | — |
| Aaron Walter Arnold | Aaron Walter Arnold | — | (760) 881 9335 | GC, remodel, ADU | Phelan · San Bernardino County | — | — |
| Aaron's Industrial Maintenance INC | Aaron Paul Smith | — | (760) 244 7609 | Other | Hesperia · San Bernardino County | — | — |
| Aaron's Painting Co | Aaron Perez Saldivar | — | (760) 333 3383 | Windows, patio, painters | Yucca Valley · San Bernardino County | — | — |
| Ab Buildco | Esly Estuardo Blanco Escobar | — | (909) 486 5552 | GC, remodel, ADU | Twin Peaks · San Bernardino County | — | — |
| Abart Construction | Fritz Gustav Gero Lapenson | — | (760) 559 0597 | GC, remodel, ADU | Apple Valley · San Bernardino County | — | — |
| Abba Communications | Abba Communications | — | (909) 944 2599 | Other | Ontario · San Bernardino County | — | — |
| Abbott Innovation Construction | Randall Glen Abbott | — | (760) 508 7540 | GC, remodel, ADU | Apple Valley · San Bernardino County | — | — |
| Abc Resources INC | Rick Eugene Schaefer | ellu@enquiry-abc.com | (909) 988 0390 | Other | Ontario · San Bernardino County | — | — |
| Abc Sheet Metal | Abc Sheet Metal | sales@abcsheetmetal.com | (951) 241 9840 | Other | San Bernardino · San Bernardino County | — | — |
| Abdo Contractors-american Rooters 4 Less | Bajis Issa Abdo | — | (909) 881 0100 | GC, remodel, ADU | San Bernardino · San Bernardino County | — | — |
| Abek Flooring INC | Juan Manuel Morales Lima | — | (310) 490 6728 | Other | Victorville · San Bernardino County | — | — |
| Abel Diaz | Abel Diaz | — | (714) 321 5741 | Electricians | Rialto · San Bernardino County | — | — |
| Abel Rodarte | Abel Rodarte | — | (909) 965 7826 | GC, remodel, ADU | Rimforest · San Bernardino County | — | — |
| Abet Quest INC | Daniel Wryan Flowers | — | (760) 912 2069 | GC, remodel, ADU | Apple Valley · San Bernardino County | — | — |
| Abl Contracting INC | William David Iii Dodds | william@ablcontracting.com | (909) 782 1029 | GC, remodel, ADU | Ontario · San Bernardino County | — | — |
| Able Contracting | Chris Anthony Esteves | — | (909) 945 7058 | GC, remodel, ADU | Alta Loma · San Bernardino County | — | — |
| Able Electric | Charles Robert Iii Gunter | — | (714) 287 4762 | Electricians | Ontario · San Bernardino County | — | — |