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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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Jefferson County ZIP Codes

Browse all ZIP Codes, cities, and associated area codes registered in Jefferson County.

County State ZIP Code City Area Codes
Jefferson County NE 68424 Plymouth 402, 531
Jefferson County NE 68429 Reynolds 402, 531, 785
Jefferson County NE 68440 Steele City 402, 531, 785
Jefferson County NY 13601 Watertown 315, 680
Jefferson County NY 13602 Fort Drum 315, 680
Jefferson County NY 13603 Watertown 315, 680
Jefferson County NY 13605 Adams 315, 680
Jefferson County NY 13606 Adams Center 315, 680
Jefferson County NY 13607 Alexandria Bay 315, 343, 613, 680, 753
Jefferson County NY 13608 Antwerp 315, 680
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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.