The First Digit of a ZIP Code
The first digit of the U.S. ZIP Code is used to represent a group of states and is the first step in organizing routes for effiicient mail delivery. The first digit of a ZIP Code (0–9) represents a broad geographic area, with lower numbers starting in the Northeast and moving toward the West. Each "zone" covers several states. This not only helps the USPS route mail efficiently throughout the country, it also serves as a quick geographic reference. Just by knowing the first digit of a ZIP Code, it tells you which part of the country it is in.
Here’s a quick reference list of ZIP Code first digits and the states they include:
- 0 – Connecticut, Massachusetts, Maine, New Hampshire, New Jersey, Puerto Rico, Rhode Island, Vermont, Virgin Islands
- 1 – Delaware, New York, Pennsylvania
- 2 – District of Columbia, Maryland, North Carolina, South Carolina, Virginia, West Virginia
- 3 – Alabama, Florida, Georgia, Mississippi, Tennessee
- 4 – Indiana, Kentucky, Michigan, Ohio
- 5 – Iowa, Minnesota, Montana, North Dakota, South Dakota, Wisconsin
- 6 – Illinois, Kansas, Missouri, Nebraska
- 7 – Arkansas, Louisiana, Oklahoma, Texas
- 8 – Arizona, Colorado, Idaho, New Mexico, Nevada, Utah, Wyoming
- 9 – Alaska, American Samoa, California, Guam, Hawaii, Marshall Islands, Federated States of Micronesia, Northern Mariana Islands, Oregon, Palau, Washington
You may notice there is some blank space in the map. That is because not every area in the United States are covered by a ZIP Code. The USPS does not service very rural and remote areas. A fair bit of Alaska, California, Nevada, Utah, Arizona, Wyoming, and New Mexico have no ZIP Code assigned, as indicated by the white space inside the states.
