California is divided into 9 separate regions. The following table gives the region number and the area that each region covers. Contact the region directly for more information.
| Region | Web Site | Area |
| 6 | www.ipa-r6.org | CA – Los Angeles, Orange, Kern, San Luis Obispo, Santa Barbara and Ventura |
| 9 | www.ipa-us-region9.com | CA – San Francisco City and County, San Mateo, Alameda, Contra Costa, & Marin |
| 23 | Uses US web site | CA – San Diego & Imperial Counties |
| 29 | www.iparegion29.com | CA – Northern (Alpine, Amador, Calaveras, Colusa, El Dorado, Mono, Nevada, Placer, Sacramento, San Joaquin, Sierra, Stanislaus, Sutter, Tuolumne, Yolo, and Yuba Counties) |
| 37 | Uses US web site | CA – Santa Clara, Santa Cruz, San Benito & Monterey |
| 40 | www.iparegion40.org | CA – Siskiyou, Modoc, Trinity, Shasta, Tehama, Glenn, Lassen, Butte, Plumas & Sierra |
| 41 | Uses US web site | CA – Del Norte, Humboldt, Lake, Napa, Mendocino, Sonoma |
| 44 | Uses US web site | CA – San Bernardino/Riverside |
| 50 | Uses US web site | CA -Napa Valley, Napa & Solano |