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. Back ...

We all have one, we know it by heart, and we share it with our neighbors. But chances are you haven't thought that much about this ubiquitous part of American life — the ZIP code. We all know about ...

The humble ZIP Code shows up in all kinds of surprising places. Planet Money looks at how it was born, how it transformed the mail and talks to one researcher who argues that it's gone too far. The ...

That used to be the ZIP code for Silver Cliff, Colorado, before the U.S. Postal Service removed it from use and forced the town to use neighboring Westcliffe’s ZIP code. “We lost our identity,” said ...