Community Identity Project:
USPS Mailing Addresses in Unincorporated Alameda County



About the Issue

USPS mailing addresses and ZIP codes in the urban unincorporated parts of Alameda County do not accurately reflect unincorporated community names or boundaries. This has unintended consequences:

  • Causes confusion
  • Impacts community identity
  • Hinders data collection
  • Influences resource allocation

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image of map showing that place names and zip cods do not align with urban unincorporated Alameda County communities

Current USPS Place Names and ZIP codes do not align with urban unincorporated Alameda County communities

EXAMPLE 1: USPS Place Names do not reflect urban unincorporated area place names.

The official USPS Place Name in the example, below, is "San Leandro" (a city) when, in fact, this address is in Ashland, an unincorporated community:

image showing that USPS Place Names do not reflect urban unincorporated area place names


EXAMPLE 2: USPS Place Name boundaries are not consistent with urban unincorporated area community boundaries.

Castro Valley and San Lorenzo have their own Post Offices and their own Place Names (PLLs), but the USPS Place Name boundaries do not match the boundaries of those communities:

image showing USPS Place Name boundaries are not consistent with urban unincorporated area community boundaries


Project History

  • Sup. Nate Miley, District 4, launched the Eden Area Livability Initiative (EALI) in 2004 with the goals of improving the quality of life and health of the residents of the urban unincorporated communities. EALI had 2 phases.
  • During EALI Phase II (2012-2019), a "ZIP Code Realignment" project arose from the Governance Working Group to address the unintentional impacts of ZIP codes and USPS place names on unincorporated community identity, data collection, and service delivery.
  • In 2019, the Governance Working Group began researching ZIP Code realignment options and processes. In 2022, Supervisor Miley requested that CDA provide further research and support for this project.
  • This project focuses on the urban unincorporated area of Alameda County because residents of these communities have expressed concern about community identity related to ZIP codes and USPS mailing addresses.