Every address in California sits inside a stack of districts. At the federal level you have a congressional district and a federal court district. At the state level, a Senate district, an Assembly district, and a Board of Equalization district. At the local level, a county supervisorial district plus a school district and usually several special districts for things like water and fire protection. The quickest way to see your state and federal legislative districts is the Legislature’s lookup tool at findyourrep.legislature.ca.gov, which returns your congressional, Senate, Assembly, and Board of Equalization districts from a street address. County and special district information lives with your county elections office.
Here is what each layer actually is, who it elects, and what that office decides.
Congressional Districts
California has 52 congressional districts, each sending one member to the U.S. House of Representatives. The U.S. Constitution requires House seats to be distributed among states in proportion to population, counted every ten years by the census.1Congress.gov. Article I Section 2 – House of Representatives After the 2020 census the state lost one seat, dropping from 53 to 52.2United States Census Bureau. Congressional Apportionment Each district now covers roughly 760,000 people. Members serve two-year terms and vote on federal matters: the national budget, defense, interstate commerce, immigration.
The congressional map is in transition. In November 2025, California voters passed Proposition 50, which temporarily replaces the Citizens Redistricting Commission’s congressional maps with maps drawn by the Legislature. The new maps take effect after the November 2026 elections and stay in use until the Commission draws fresh maps following the 2030 census.3Senate Office of Demographics. 2025 Congressional Districts The total count stays at 52.4Legislative Analyst’s Office. Proposition 50 – Ballot Analysis If you look up your congressional district before the 2026 election and again after, the number may change.
State Senate Districts
California’s State Senate has 40 members, each elected from a separate district under Article IV of the state Constitution. Senators serve four-year terms, and half the seats are on the ballot every two years.5California Legislative Information. California Constitution Article IV – Legislative
Splitting roughly 40 million residents among 40 districts means each state Senator represents close to one million people. That is the highest ratio of any state senate in the country. In rural stretches of the state a single district covers a vast geographic area; in dense urban counties, a district may fit inside part of one city. Senators vote on the state budget, confirm gubernatorial appointments, and review bills that originate in the Assembly.
State Assembly Districts
The Assembly, California’s lower house, has 80 members. Each Assembly district is roughly half the population of a Senate district, and Assembly Members serve two-year terms.5California Legislative Information. California Constitution Article IV – Legislative Most state legislation starts in the Assembly before moving to the Senate. Because the districts are smaller and the term is shorter, an Assembly Member’s district office is often the most responsive first stop for a constituent dealing with a state agency.
Board of Equalization Districts
The Board of Equalization is the layer most Californians have never heard of. The state is divided into just four Board of Equalization districts under Article XIII, Section 17 of the California Constitution, each electing one member.6Justia. California Constitution Article XIII Section 17 – Taxation A fifth seat is held by the State Controller, elected statewide. Each elected member represents about 10 million constituents.7California State Board of Equalization. About BOE
The Board is a specialized tax body, not a general legislature. Its main job today is property tax oversight: it audits the assessment practices of all 58 county assessors to keep valuations uniform, and it directly assesses certain state-assessed properties such as railroads, public utilities, and multi-county pipelines, then allocates those values to local jurisdictions. The Board also still administers the Alcoholic Beverage Tax and the Tax on Insurers.
County Supervisorial Districts
Each of California’s 58 counties is governed by a board of supervisors elected from supervisorial districts. Most counties have five. Supervisors control the county budget, set land-use policy for unincorporated areas, and oversee services such as public health, the sheriff’s department, and county roads.
The population these seats represent varies more than any other district type in the state. Los Angeles County’s five supervisors each represent roughly two million people, which makes a single L.A. County supervisorial district larger than the populations of many entire states. In rural counties, a supervisor may represent only a few thousand residents. Boundaries are redrawn after each census to keep populations roughly equal within a given county.
Special Districts and School Districts
California has roughly 2,000 independent special districts. Under state law, a special district is a local agency that is not a city, county, school district, or community college district, and that performs a limited set of functions within a defined area. Water districts, fire protection districts, irrigation districts, park and recreation districts, and public utility districts are the common types.
Most special districts are governed by elected boards, though some have appointed officials or are run by city or county officials in an ex officio role. Funding usually comes from a mix of property tax revenue and user fees. If you see line-item assessments on your property tax bill you don’t recognize, those are typically special district charges tied to services available at your address.
California also has 937 school districts as of the 2024–25 fiscal year.8California Department of Education. List of School Districts School districts are not classified as special districts under state law, but they work the same way from the resident’s perspective: elected boards, defined boundaries, and independent taxing authority. A typical Californian lives inside at least half a dozen overlapping districts at any given time.
Federal Court Districts
California is also split for federal court purposes. The state falls within the Ninth Circuit Court of Appeals, which covers the western United States and is the largest federal appellate circuit by both geography and caseload.9United States Courts. About the U.S. Courts of Appeals At the trial level, four federal district courts cover the state: the Northern, Eastern, Central, and Southern Districts of California. These boundaries decide where a federal lawsuit must be filed. They do not involve any elected representative, so they will not appear in a legislative lookup tool.
Who Draws the Lines
Article XXI of the California Constitution assigns redistricting to the California Citizens Redistricting Commission, an independent 14-member body. The Commission is made up of five members registered with the state’s largest political party, five from the second-largest party, and four who belong to neither, a composition designed to keep any single party from controlling the maps.10California Legislative Information. California Constitution Article XXI – Redistricting
The Commission redraws congressional, State Senate, Assembly, and Board of Equalization lines in the year after each decennial census, working from a constitutionally ranked set of criteria: equal population, Voting Rights Act compliance, contiguity, keeping cities and communities together, compactness, and nesting Assembly districts inside Senate districts where feasible.11Justia. California Constitution Article XXI Section 2 – Redistricting of Senate, Assembly, Congressional and Board of Equalization Districts Final maps need yes votes from at least three Democratic, three Republican, and three unaffiliated commissioners before taking effect.12California Citizens Redistricting Commission. FAQs County supervisorial lines are drawn separately by each county after the census, following the same equal-population principle.
Proposition 50, passed in November 2025, is a temporary exception for congressional maps only. State legislative and Board of Equalization districts remain on the Commission’s maps.
Looking Up Your Districts
For your congressional, State Senate, State Assembly, and Board of Equalization districts, use the Legislature’s address lookup at findyourrep.legislature.ca.gov. It returns the district numbers and the current representative for each, with contact information. For your county supervisorial district, check your county’s elections office or board of supervisors website. For school and special districts, your property tax bill lists the ones that assess your parcel, and your county assessor can confirm the full set.