Learn the history and meaning of usps postal codes, why it's called a ZIP code, whether a postal code is a ZIP code, and what ZIP code numbers stand for.

On July 1, 1963, the U.S. Post Office Department introduced the ZIP code program to get a handle on the heaping surplus of mail. Today, those five digits represent much more for American society.

The House passed two bills Monday night that would authorize the U.S. Postal Service to create 76 new ZIP codes for communities nationwide.  These ...

New USPS delivery standards could slow mail for some customers and speed it up for others. Here's what online shoppers need to know.

The Postal Service’s plans will delay a third of mail in 27 states, according to a Washington Post analysis, hitting states west of the Rocky Mountains especially hard.