| 1999 Roofing LLC | Hernandez-escalera Fernando | — | (831) 325 7097 | Other roofers | Salinas · Monterey County | — | — |
| 1A Garage Doors INC | Vadim Kalenyuk | — | (916) 838 8182 | Other | Rancho Cordova · Sacramento County | — | — |
| 1H Electric LLC | Bryan Ray Howell | — | (559) 260 1729 | Electricians | Lemoore · Kings County | — | — |
| 1ichard A Mathews | 1ichard A Mathews | — | (951) 322 6727 | GC, remodel, ADU | Lake Elsinore · Riverside County | — | — |
| 1M Enterprises INC | Nicholas Ryan Fleming | — | (760) 697 6999 | GC, remodel, ADU | Oceanside · San Diego County | — | — |
| 1P Electric | Juan Pablo Zamora Garcia | contact@1pelectric.com | (510) 826 6905 | Electricians | Hayward · Alameda County | — | — |
| 1quality Construction Corp | Jose Luis Hernandez Tellez | — | (760) 310 6308 | GC, remodel, ADU | Vista · San Diego County | — | — |
| 1st Action Restoration | 1st Action Restoration | — | (855) 379 9257 | GC, remodel, ADU | Mission Viejo · Orange County | — | — |
| 1st Affordable Contractor.com | 1st Affordable Contractor.com | — | (714) 931 1776 | GC, remodel, ADU | Garden Grove · Orange County | — | — |
| 1st Aid Drainage & Plumbing INC | Ricardo Bernal | — | (619) 454 2704 | Other | Lemon Grove · San Diego County | — | — |
| 1st Atrium INC | Arne Edgar Perthus | — | (760) 880 6606 | Electricians | Palm Desert · Riverside County | — | — |
| 1st Call Building Solutions | 1st Call Building Solutions | — | (323) 901 4832 | GC, remodel, ADU | Palmdale · Los Angeles County | — | — |
| 1st Call Refrigeration INC | Todd Anthony Garcia | — | (714) 951 6383 | HVAC | Whittier · Los Angeles County | — | — |
| 1st Century Builders INC | Colin Tuan Pratt | — | (818) 254 7183 | GC, remodel, ADU | Agoura Hills · Los Angeles County | — | — |
| 1st Choice Air Solutions | Moises Rene Vanegas | — | (323) 667 4149 | HVAC | San Bernardino · San Bernardino County | — | — |
| 1st Choice Backflow And Construction | Henry George Kohlmann | — | (760) 468 4026 | GC, remodel, ADU | Bonsall · San Diego County | — | — |
| 1st Choice Builders Group INC | Richard Roy Hayden | — | (951) 378 5639 | GC, remodel, ADU | Anaheim · Orange County | — | — |
| 1st Choice Builders INC | Sonia Mardirossian | — | (818) 433 4971 | GC, remodel, ADU | Van Nuys · Los Angeles County | — | — |
| 1st Choice Construction & Restoration INC | Onik Stepani Hakopian | — | (818) 370 1590 | GC, remodel, ADU | Glendale · Los Angeles County | — | — |
| 1st Choice Construction Co | Nathaniel Leroy Duncan | — | (760) 851 8821 | GC, remodel, ADU | Riverside · Riverside County | — | — |
| 1st Choice Construction Services INC | Elvira Plasichuk | — | (916) 952 3226 | GC, remodel, ADU | Rancho Cordova · Sacramento County | — | — |
| 1st Choice Construction Solutions | Sean Franklin Dooley | — | (949) 290 9462 | GC, remodel, ADU | Mission Viejo · Orange County | — | — |
| 1st Choice Design & Development | Tony Gene Holder | — | (844) 292 3700 | Electricians | Orange · Orange County | — | — |
| 1st Choice Drywall INC | Rogelio Silva-Espitia | — | (619) 799 8404 | Other | Lemon Grove · San Diego County | — | — |
| 1st Choice Electric Enterprises INC | Marcos Antonio Vazquez | — | (209) 809 5021 | Electricians | Modesto · Stanislaus County | — | — |
| 1st Choice Electric INC | Jerrett Scott Bruemmer | — | (909) 247 5849 | Electricians | Norco · Riverside County | — | — |
| 1st Choice Electric Service | James Dale Smith | 1stchoiceelectricservice@gmail.com | (415) 328 5711 | Electricians | Fairfield · Solano County | — | — |
| 1st Choice General Services INC | Sebastian Jr Rodriguez | — | (818) 602 1501 | GC, remodel, ADU | North Hills · Los Angeles County | — | — |
| 1st Choice Handyman | 1st Choice Handyman | — | (720) 252 6240 | GC, remodel, ADU | Torrance · Los Angeles County | — | — |
| 1st Choice Heating & Air Conditioning INC | Christopher Scott Solar | — | (949) 305 5754 | HVAC | Lake Forest · Orange County | — | — |
| 1st Choice Home Improvement | 1st Choice Home Improvement | — | (714) 288 1888 | GC, remodel, ADU | San Clemente · Orange County | — | — |
| 1st Choice Painting | 1st Choice Painting | — | (661) 972 3782 | Windows, patio, painters | Tehachapi · Kern County | — | — |
| 1st Choice Plumbing Heating And Air | Fernando Andres Jr Rojas | — | (760) 696 1201 | HVAC | Oceanside · San Diego County | — | — |
| 1st Choice Pool & Spa Solutions | Castillo Ruiz David | — | (949) 355 9396 | Pool | Lake Forest · Orange County | — | — |
| 1st Choice Renovators LLC | Ignacio Jr Zamora | — | (909) 630 3936 | GC, remodel, ADU | Phelan · San Bernardino County | — | — |
| 1st City Electrical Contractors | Robert William Griffin | — | (213) 595 1564 | Electricians | Compton · Los Angeles County | — | — |
| 1st Class Access Control | Donald Duane Slayton | service@1stclassaccesscontrol.com | (805) 955 9230 | Other | Simi Valley · Ventura County | — | — |
| 1st Class Blinds And Shutters | 1st Class Blinds And Shutters | — | (209) 838 8278 | Other | Escalon · San Joaquin County | — | — |
| 1st Class Builder | 1st Class Builder | — | (626) 826 2319 | GC, remodel, ADU | La Puente · Los Angeles County | — | — |
| 1st Class Construction INC | Troy Anthony Ross | — | (209) 617 8452 | GC, remodel, ADU | Patterson · Stanislaus County | — | — |