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.

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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 94942 Mill Valley Marin County 415
CA 94945 Novato Marin County 415, 628, 707
CA 94946 Nicasio Marin County 415, 628, 707
CA 94947 Novato Marin County 415, 628, 707
CA 94948 Novato Marin County 415
CA 94949 Novato Marin County 415, 628
CA 94950 Olema Marin County 415, 628
CA 94951 Penngrove Sonoma County 707
CA 94952 Petaluma Sonoma County 415, 628, 707
CA 94953 Petaluma Sonoma County 707
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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.