CA DOI Zones

The California Department of Insurance (DOI) has divided California into eight zones and six sub zones (generally corresponding to counties) to help insurance companies manage their total exposures.

Generally speaking, the higher in the alphabet the greater the risk (Zones A and B = high risk, Zones F, G, and H = less risk).

Zone name Counties
A1
  • San Francisco
  • San Mateo
A2
  • Alameda
  • Contra costa
A3
  • Del Norte
  • Humboldt
  • Lake
  • Marin
  • Mendocino
  • Monterey
  • Napa
  • San Benito
  • Santa Clara
  • Santa Cruz
  • Solano
  • Sonoma
B1
  • Los Angeles county west of Interstate 5 and south of Mulholland Drive
B2
  • Remainder of Los Angeles county area not covered by zone B1
B3
  • Orange
C
  • Kern
  • San Luis Obispo
  • Santa Barbara
  • Ventura
D

San Diego

E
  • Alpine
  • Imperial
  • Inyo
  • Mono
  • Riverside
  • San Bernardino
F
  • Fresno
  • Kings
  • Madera
  • Mariposa
  • Merced
  • Tulare
G
  • Amador
  • Butte
  • Calaveras
  • Colusa
  • El Dorado
  • Glenn
  • Nevada
  • Placer
  • Sacramento
  • San Joaquin
  • Stanislaus
  • Sutter
  • Tuolumne
  • Yolo
  • Yuba
H
  • Lassen
  • Modoc
  • Plumas
  • Shasta
  • Sierra
  • Siskiyou
  • Tehama
  • Trinity