Every ten years, districts must be redrawn so that each supervisorial district is substantially equal in population. This process, called redistricting, is important in ensuring that each board member represents about the same number of constituents. The San Bernardino County Board of Supervisors is responsible for drawing supervisorial districts.
The Board of Supervisors has adopted an ordinance establishing an Advisory Redistricting Commission, similar to that of other local boards and commissions, consisting of San Bernardino County residents and retired judges selected through a specific application process and final appointment by the Board of Supervisors. The Advisory Redistricting Commission is required to recommend to the Board of Supervisors a minimum of two possible supervisorial district maps. Redistricting is done using U.S. Census data, which is expected to be released around September 30, 2021. For San Bernardino County, the redistricting process must be completed by December 15, 2021.