Browse all 40,000+ United States ZIP codes by state. Find ZIP codes by city, address, county, or area code — free and always up to date.
ZIP codes (Zone Improvement Plan) were introduced by the USPS in 1963 to improve mail sorting efficiency. The original 5-digit format divides the country into delivery zones from northeast (0XXXX) to the west coast (9XXXX). The ZIP+4 extension was added later to enable even more precise delivery routing down to a specific street block or building.
There are approximately 41,000–43,000 active ZIP codes in the United States, spread across all 50 states, Washington D.C., Puerto Rico, Guam, and other territories. About 2,000 ZIP codes change every year as the USPS updates its routing system.