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City ZIP codes · California

Castro Valley, CA ZIP Codes

2 ZIP codes use the postal name Castro Valley, California (Census 2020 ZCTAs and GeoNames postal codes, October 2026), all residential. Median household income runs from $128,385 in 94546 to $212,605 in 94552, 1.7 times as much (Census Bureau, ACS 2020-2024). Castro Valley's most populous ZIP code is 94546, with 44,855 people (ACS 2020-2024); 43% of its land is in the city of Castro Valley.

  • ACS2020-24
  • Census2020
  • GeoNames2026

Where are Castro Valley's ZIP codes?

94546: $128k median household income94552: $213k median household income945529454694546: $128k median household income94552: $213k median household income945529454694546: $128k median household income94552: $213k median household income9455294546
The 2 residential ZIP codes named Castro Valley, shaded by median household income in national fifths (ACS 2020-2024). Select a ZIP to open it. <$54.1k$98.1k+no figure

Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).

How different are Castro Valley's ZIP codes?

The highest median household income is in 94552 ($212,605), the lowest in 94546 ($128,385). Home values run from $1,043,500 in 94546 to $1,394,300 in 94552.

Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B19013, B25077, B01003).

All 2 residential ZIP codes of Castro Valley

Residential ZIP codes with the postal name Castro Valley, CA, largest first (ACS 2020-2024); sort by any column
County
94546 Alameda County 44,855 2,811 $128k $1.04M
94552 Alameda County 14,506 280 $213k $1.39M

Download the 2 ZIP codes as CSV

Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; 2023 Gazetteer land areas (2020 ZCTAs); town names from simplemaps US ZIP Codes (CC BY 4.0) and GeoNames (CC BY 4.0).

Which counties do Castro Valley's ZIP codes reach?

Castro Valley's residential ZIP codes lie in Alameda County.

Which places do Castro Valley's ZIP codes cover?

A postal name is not a city limit. By the Census Bureau's places, Castro Valley's residential ZIP codes cover Castro Valley itself and 1 other place, each listed with the ZIP codes that have at least 5% of their land in it or hold most of the place:

Source: U.S. Census Bureau, 2020 ZCTA-to-place relationship file (shares of land).

Which first three digits do Castro Valley's ZIP codes use?

The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. Every ZIP code of Castro Valley starts with 945.

Three-digit prefixes of Castro Valley's ZIP codes, the sectional center for each (USPS labeling list L005, effective October 1, 2026) and how many of the prefix's codes are Castro Valley's
PrefixSectional centerHereAll codes
945 Oakland, CA (SCF 945) 2 93

Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.