| Innovative Stone | David Patrick Worrell | — | (530) 878 5022 | Other | Auburn · Placer County | — | — |
| Innovative Windows & Glass | Innovative Windows & Glass | info@innovativewg.com | (916) 964-5277 | Windows, patio, painters | Rocklin · Placer County | — | — |
| Innovative Windows And Glass | Innovative Windows And Glass | — | (916) 741 9981 | Windows, patio, painters | Rocklin · Placer County | — | — |
| Insight Construction | Aaron Lang Berthelsen | — | (916) 742 2395 | GC, remodel, ADU | Granite Bay · Placer County | — | — |
| Insulation Solutions | Robert Giles | — | (530) 274 1343 | Other | Rocklin · Placer County | — | — |
| Intech Mechanical Company LLC | Richard Bill Chowdry | — | (916) 797 4900 | HVAC | Roseville · Placer County | — | — |
| Integrated Designs | Integrated Designs | design@somam.com | (916) 771 0327 | Other | Granite Bay · Placer County | — | — |
| Integrated Facilities Services | Ryan Christopher Baird | — | (916) 462 7900 | GC, remodel, ADU | Loomis · Placer County | — | — |
| Integricon Builders DBA On The Rock Concrete Artisans | Ken Avila | — | (530) 368 6623 | GC, remodel, ADU | Auburn · Placer County | — | — |
| Integrity Painting | Integrity Painting | — | (530) 401 6711 | Windows, patio, painters | Auburn · Placer County | — | — |
| Integrity Tile | Integrity Tile | — | (530) 613 2242 | Other | Auburn · Placer County | — | — |
| Intelligent Development INC | Philip Lincoln Hawkins | — | (530) 320 4775 | GC, remodel, ADU | Roseville · Placer County | — | — |
| Inter-connect LLC | Carlos Manuel Alpizar Rivera | — | (916) 283 1534 | Other | Roseville · Placer County | — | — |
| Interstate Construction INC | Robert Alan Riedel | — | (916) 357 5477 | HVAC | Roseville · Placer County | — | — |
| Intrust Properties INC | James Richard Burkett | — | (916) 847 8849 | Other | Lincoln · Placer County | — | — |
| Investco Construction Company | Bradley Dylan Rose | — | (916) 251 8599 | GC, remodel, ADU | Loomis · Placer County | — | — |
| Irie Remodeling And Construction INC | Taylor Jay Washburn | — | (916) 995 6853 | GC, remodel, ADU | Lincoln · Placer County | — | — |
| Iron Elegance | Enrico Louis Salvatore | — | (916) 362 3263 | GC, remodel, ADU | Rocklin · Placer County | — | — |
| Iron Oak Construction INC | Mark Eugene Sirmans | — | (916) 764 6930 | GC, remodel, ADU | Newcastle · Placer County | — | — |
| Iron Oak Enterprises | Robert William Lawson | — | (916) 205 7322 | GC, remodel, ADU | Newcastle · Placer County | — | — |
| Iron Oak Plumbing INC | Gary Louis Ferrari | — | (916) 782 9565 | Other | Rocklin · Placer County | — | — |
| Iron Stone Electric | Joel Gomez | — | (916) 960 9615 | Electricians | Lincoln · Placer County | — | — |
| Iron Wolf Construction | Joseph Anthony Lopez | — | (916) 673 8913 | GC, remodel, ADU | Rocklin · Placer County | — | — |
| Ironwood Carpentry | Ironwood Carpentry | — | (530) 305 8267 | Other | Applegate · Placer County | — | — |
| Ironwood Construction Co | David Allen Glenwinkel | — | (530) 217 4530 | GC, remodel, ADU | Auburn · Placer County | — | — |
| Is INC | Anne F Crawford | — | (916) 920 1700 | Other | Roseville · Placer County | — | — |
| Island Pools And Spas | Island Pools And Spas | — | (916) 869 9201 | Pool | Rocklin · Placer County | — | — |
| Ismael Isidro Tree Care | Ismael Isidro Tree Care | — | (916) 367 8240 | Tree | Lincoln · Placer County | — | — |
| Isotech Environmental Corporation | Mohammad Hossain Faridnia | — | (408) 281 2927 | GC, remodel, ADU | Granite Bay · Placer County | — | — |
| Ivy Screen INC DBA Back Yard Dream | Jerry Joseph Ponzo | — | (916) 806 3882 | GC, remodel, ADU | Newcastle · Placer County | — | — |
| Izba Development | Alex Vladimirovic Vilchitsa | — | (916) 628 6975 | GC, remodel, ADU | Meadow Vista · Placer County | — | — |
| J & D Excavation INC | James Allen Hudson | — | (916) 521 7365 | Other | Meadow Vista · Placer County | — | — |
| J & H Mechanical Heating And Air | Juan Pimentel Hernandez | — | (916) 519 6225 | HVAC | Roseville · Placer County | — | — |
| J & J Custom Glazing INC | Bradley Steven Grenell | jjcustomglazing@gmail.com | (530) 852 2382 | Windows, patio, painters | Auburn · Placer County | — | — |
| J & L Electric | Jeremy Robert Rich | — | (916) 505 3070 | Electricians | Rocklin · Placer County | — | — |
| J A European Design | J A European Design | — | (916) 716 0129 | Other | Auburn · Placer County | — | — |
| J A L Electric Co | Joseph Ahmad Larian | — | (916) 634 5340 | Electricians | Rocklin · Placer County | — | — |
| J Allan Communications INC | James Allan Williams | — | (916) 765 1511 | Other | Rocklin · Placer County | — | — |
| J And J Construction | Jason Dean Gallamore | — | (916) 645 3151 | Electricians | Lincoln · Placer County | — | — |
| J B Excavating | J B Excavating | — | (916) 871 6333 | Other | Applegate · Placer County | — | — |