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
All states and U.S. territories
Maps and coordinates
State directory

Illinois ZIP Codes

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

State ZIP Code City County Area Codes
IL 62017 Coffeen Montgomery County 217, 447, 618
IL 62018 Cottage Hills Madison County 618
IL 62019 Donnellson Montgomery County 217, 447, 618
IL 62021 Dorsey Madison County 618
IL 62022 Dow Jersey County 618
IL 62023 Eagarville Macoupin County 217, 447
IL 62024 East Alton Madison County 618
IL 62025 Edwardsville Madison County 618
IL 62026 Edwardsville Madison County 618
IL 62027 Eldred Greene County 217, 447, 618
Page 101 of 159

Geographic Map of Illinois

Postal context

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.