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 ...

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 ...

Everyone knows the ZIP code 90210—but what about these other notable codes around the country? The Zone Improvement Plan, otherwise known as the ZIP code, is the network of postal codes the U.S.