One of the advantages for employees in a group health plan is the contribution most employers make toward the cost of the health coverage premium â in many cases, employers pay one-half or more of the monthly premium for an employee.
The basic format consists of five decimal numerical digits. An extended ZIP+4 code, introduced in 1983, includes the five digits of the ZIP code, a hyphen, and four additional digits that determine a more specific location within a given ZIP code. The USPS provides a free online lookup tool for ZIP codes.
In 1983, the USPS changed its ZIP Code system to include the new ZIP+4. A ZIP+4 Code uses the basic five-digit code plus four additional digits to identify a small delivery segment such as a street, a city block, a group of apartments, or even an individual address that receives a high volume of mail.