U.S. postal lookup

U.S. ZIP Codes Database 2026

Search by ZIP code, city, county, or state and find clear postal details with maps, time zones, and area code data.

42,735 verified records
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California ZIP Codes

Complete postal directory, details, and geographic map for the State of California.

State ZIP Code City County Area Codes
CA 94573 Rutherford Napa County 707
CA 94574 Saint Helena Napa County 707
CA 94575 Moraga Contra Costa County 925
CA 94576 Deer Park Napa County 707
CA 94577 San Leandro Alameda County 341, 510
CA 94578 San Leandro Alameda County 341, 510
CA 94579 San Leandro Alameda County 341, 510
CA 94580 San Lorenzo Alameda County 341, 510
CA 94581 Napa Napa County 707
CA 94582 San Ramon Contra Costa County 925
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About U.S. ZIP Codes

ZIP codes are a United States Postal Service system introduced in 1963 to make mail routing more accurate and efficient. The standard format uses five digits, while ZIP+4 adds four more digits for a more precise delivery segment.

ZIP codes cover the United States, its territories, military mail routes, and other USPS delivery points. This directory organizes that data for practical lookup by ZIP code, city, county, and state.