42,000 ZIP Codes

Quick! What’s that ZIP Code?  

There are nearly 42,000 ZIP Codes in the country. They range from 00501, belonging to the Internal Revenue Service in Holtsville, NY, to 99950 in Ketchikan, AK.

Easiest to remember? How about 12345, a unique ZIP Code for General Electric in Schenectady, NY.

The Zone Improvement Plan — ZIP — was introduced in 1963. The first number represents a general geographic area of the nation, such as “0” in the East moving to “9” in the West. The next two numbers are for regional areas and the final two are for specific Post Offices.

Make it a ZIP+4 — introduced in 1983 — and mail can be sorted to specific streets, buildings, houses and businesses.

Today, ZIP Codes are important parts of the nation’s 911 emergency system.