ZIP code 94552: Castro Valley, CA
ZIP code 94552 is in Castro Valley (95% of residents), in Alameda County, California. 5.1% of its residents live outside city limits. It is in California's 10th congressional district (73%) and California's 14th congressional district (27%). Its state senate districts are State Senate District 9 (97%), State Senate District 10 (2.0%) and State Senate District 5 (0.7%); its state house districts are Assembly District 20 (97%) and Assembly District 16 (2.5%).
See it on the mapAll of California
City and county
| City or town | Share of ZIP residents |
|---|---|
| Castro Valley | 95% |
| Hayward | 0.3% |
| Fairview | 0.1% |
| Union City | 0.1% |
| County | Share of ZIP residents |
|---|---|
| Alameda County | 100% |
| Town or county subdivision | Share of ZIP residents |
|---|---|
| Hayward CCD | 99% |
| Fremont CCD | 0.5% |
| Livermore-Pleasanton CCD | 0.5% |
Congressional districts
| Congressional district | Share of ZIP residents |
|---|---|
| California's 10th congressional district (CA-10) | 73% |
| California's 14th congressional district (CA-14) | 27% |
This ZIP is split between districts. A mailing address in it could be in either; the map or locate_point gives the district for an exact address.
Elected officials
| Office | Member | Contact | Share of residents |
|---|---|---|---|
| U.S. Representative (CA-10) | Mark DeSaulnier (D) | 202-225-2095 | 73% |
| U.S. Representative (CA-14) | Aisha Wahab (D) | 202-225-5065 | 27% |
| U.S. Senator | Adam B. Schiff (D) | 202-224-3841 | statewide |
| U.S. Senator | Alex Padilla (D) | 202-224-3553 · contact form | statewide |
| State Senator (State Senate District 9) | Tim Grayson (Democratic) | 925-258-1176 | 97% |
| State Senator (State Senate District 5) | Jerry McNerney (Democratic) | 209-472-9535 | 0.7% |
| Assembly Member (Assembly District 20) | Liz Ortega (Democratic) | 510-583-8818 | 97% |
| Assembly Member (Assembly District 16) | Rebecca Bauer-Kahan (Democratic) | 925-244-1600 | 2.5% |
| Assembly Member (Assembly District 24) | Alex Lee (Democratic) | 408-262-2501 | <0.1% |
Elected in 2024 under CA's previous congressional map; this district's lines changed for the 120th Congress (seated January 3, 2027).
Officials serving now (members of Congress until January 3, 2027). Sources: State legislators: Open States (public domain); Members of Congress: the @unitedstates project, congress-legislators (CC0).
Local government
- Castro Valley laws: search for the Castro Valley, California code of ordinances
- Alameda County website: https://www.acgov.org/
- Alameda County laws: search for the Alameda County, California code of ordinances
State legislative districts
| State senate district | Share of ZIP residents |
|---|---|
| State Senate District 9 | 97% |
| State Senate District 10 | 2.0% |
| State Senate District 5 | 0.7% |
| State house district | Share of ZIP residents |
|---|---|
| Assembly District 20 | 97% |
| Assembly District 16 | 2.5% |
| Assembly District 24 | land only |
Voting precincts
28 voting precincts overlap ZIP 94552. Map them, with each precinct's share of the ZIP's residents.
Get this in your AI agent
Your agent can get these cities, counties, districts and precincts with their shares, and their GeoJSON boundaries, from Boundary Atlas. Add https://atlas-production-d344.up.railway.app/mcp to Claude, ChatGPT, Cursor or Codex (free, no key; how), then:
related_geographies(id="us:zcta:94552")
ZIP 94552 here is the Census Bureau's ZIP Code Tabulation Area, which approximates the USPS ZIP Code; PO-box-only ZIPs have none. Districts are the maps in force for the November 3, 2026 election.